Small RNA sequencing identifies cucumber miRNA roles in waterlogging-triggered adventitious root primordia formation. Xu Xuewen,Wang Kaixuan,Pan Jiawei,Chen Xuehao Molecular biology reports The formation of adventitious roots (ARs) is a key morphological adaptation of cucumber (Cucumis sativus L.) to waterlogging stress. MicroRNAs (miRNAs) constitute a group of non-coding small RNAs (sRNA) that play crucial roles in regulating diverse biological processes, including waterlogging acclimation. However, which specific miRNAs and how they are involved in waterlogging-triggered de novo AR primordia formation are not fully known. Here, Illumina sRNA sequencing was applied to sequence six sRNA libraries generated from the waterlogging-tolerant cucumber Zaoer-N after 48 h of waterlogging and the control. A total of 358 cucumber miRNAs, 312 known and 46 novel, were obtained. Among them, 23 were differentially expressed, with 10 and 13 being up- and downregulated, respectively. A qPCR expression study confirmed that the identified differentially expressed miRNAs were credible. A total of 657 putative miRNA target genes were predicted for the 23 miRNAs using an in silico approach. A gene ontology enrichment analysis revealed that target genes functioning in cell redox homeostasis, cytoskeleton, photosynthesis and cell growth were over-represented. In total, 58 of the 657 target genes showed inverse expression patterns compared with their respective miRNAs through a combined analysis of sRNA- and RNA-sequencing-based transcriptome datasets using the same experimental design. The target gene annotation included a peroxidase, a GDSL esterases/lipase and two heavy metal-associated isoprenylated plant proteins. Our results provide an important framework for understanding the unique miRNA patterns seen in responses to waterlogging and the miRNA-mediated formation of de novo AR primordia in cucumber. 10.1007/s11033-019-05084-z
    Waterlogging of Winter Crops at Early and Late Stages: Impacts on Leaf Physiology, Growth and Yield. Ploschuk Rocío Antonella,Miralles Daniel Julio,Colmer Timothy David,Ploschuk Edmundo Leonardo,Striker Gustavo Gabriel Frontiers in plant science Waterlogging is expected to increase as a consequence of global climate change, constraining crop production in various parts of the world. This study assessed tolerance to 14-days of early- or late-stage waterlogging of the major winter crops wheat, barley, rapeseed and field pea. Aerenchyma formation in adventitious roots, leaf physiological parameters (net photosynthesis, stomatal and mesophyll conductances, chlorophyll fluorescence), shoot and root growth during and after waterlogging, and seed production were evaluated. Wheat produced adventitious roots with 20-22% of aerenchyma, photosynthesis was maintained during waterlogging, and seed production was 86 and 71% of controls for early- and late-waterlogging events. In barley and rapeseed, plants were less affected by early- than by late-waterlogging. Barley adventitious roots contained 19% aerenchyma, whereas rapeseed did not form aerenchyma. In barley, photosynthesis was reduced during early-waterlogging mainly by stomatal limitations, and by non-stomatal constraints (lower mesophyll conductance and damage to photosynthetic apparatus as revealed by chlorophyll fluorescence) during late-waterlogging. In rapeseed, photosynthesis was mostly reduced by non-stomatal limitations during early- and late-waterlogging, which also impacted shoot and root growth. Early-waterlogged plants of both barley and rapeseed were able to recover in growth upon drainage, and seed production reached . 79-85% of the controls, while late-waterlogged plants only attained 26-32% in seed production. Field pea showed no ability to develop root aerenchyma when waterlogged, and its photosynthesis (and stomatal and mesophyll conductances) was rapidly decreased by the stress. Consequently, waterlogging drastically reduced field pea seed production to 6% of controls both at early- and late-stages with plants being unable to resume growth upon drainage. In conclusion, wheat generates a set of adaptive responses to withstand 14 days of waterlogging, barley and rapeseed can still produce significant yield if transiently waterlogged during early plant stages but are more adversely impacted at the late stage, and field pea is not suitable for areas prone to waterlogging events of 14 days at either growth stage. 10.3389/fpls.2018.01863
    Soil and Crop Management Practices to Minimize the Impact of Waterlogging on Crop Productivity. Manik S M Nuruzzaman,Pengilley Georgina,Dean Geoffrey,Field Brian,Shabala Sergey,Zhou Meixue Frontiers in plant science Waterlogging remains a significant constraint to cereal production across the globe in areas with high rainfall and/or poor drainage. Improving tolerance of plants to waterlogging is the most economical way of tackling the problem. However, under severe waterlogging combined agronomic, engineering and genetic solutions will be more effective. A wide range of agronomic and engineering solutions are currently being used by grain growers to reduce losses from waterlogging. In this scoping study, we reviewed the effects of waterlogging on plant growth, and advantages and disadvantages of various agronomic and engineering solutions which are used to mitigate waterlogging damage. Further research should be focused on: cost/benefit analyses of different drainage strategies; understanding the mechanisms of nutrient loss during waterlogging and quantifying the benefits of nutrient application; increasing soil profile de-watering through soil improvement and agronomic strategies; revealing specificity of the interaction between different management practices and environment as well as among management practices; and more importantly, combined genetic, agronomic and engineering strategies for varying environments. 10.3389/fpls.2019.00140
    Elucidating the morpho-physiological adaptations and molecular responses under long-term waterlogging stress in maize through gene expression analysis. Kaur Gurwinder,Vikal Yogesh,Kaur Loveleen,Kalia Anu,Mittal Amandeep,Kaur Dasmeet,Yadav Inderjit Plant science : an international journal of experimental plant biology Waterlogging stress in maize is one of the emerging abiotic stresses in the current climate change scenario. To gain insights in transcriptional reprogramming during late hours of waterlogging stress under field conditions, we aimed to elucidate the transcriptional and anatomical changes in two contrasting maize inbreds viz. I110 (susceptible) and I172 (tolerant). Waterlogging stress reduced dry matter translocations from leaves and stems to ears, resulting in a lack of sink capacity and inadequate grain filling in I110, thus decreased the grain yield drastically. The development of aerenchyma cells within 48 h in I172 enabled hypoxia tolerance. The upregulation of alanine aminotransferase, ubiquitin activating enzyme E1, putative mitogen activated protein kinase and pyruvate kinase in I172 suggested that genes involved in protein degradation, signal transduction and carbon metabolism provided adaptive mechanisms during waterlogging. Overexpression of alcohol dehydrogenase, sucrose synthase, aspartate aminotransferase, NADP dependent malic enzyme and many miRNA targets in I110 indicated that more oxygen and energy consumption might have shortened plant survival during long-term waterlogging exposure. To the best of our knowledge, this is the first report of transcript profiling at late stage (24-96 h) of waterlogging stress under field conditions and provides new visions to understand the molecular basis of waterlogging tolerance in maize. 10.1016/j.plantsci.2021.110823
    Responses to K deficiency and waterlogging interact via respiratory and nitrogen metabolism. Cui Jing,Abadie Cyril,Carroll Adam,Lamade Emmanuelle,Tcherkez Guillaume Plant, cell & environment K deficiency and waterlogging are common stresses that can occur simultaneously and impact on crop development and yield. They are both known to affect catabolism, with rather opposite effects: inhibition of glycolysis and higher glycolytic fermentative flux, respectively. But surprisingly, the effect of their combination on plant metabolism has never been examined precisely. Here, we applied a combined treatment (K availability and waterlogging) to sunflower (Helianthus annuus L.) plants under controlled greenhouse conditions and performed elemental quantitation, metabolomics, and isotope analyses at different sampling times. Whereas separate K deficiency and waterlogging caused well-known effects such as polyamines production and sugar accumulation, respectively, waterlogging altered K-induced respiration enhancement (via the C -branched acid pathway) and polyamine production, and K deficiency tended to suppress waterlogging-induced accumulation of Krebs cycle intermediates in leaves. Furthermore, the natural N/ N isotope composition (δ N) in leaf compounds shows that there was a change in nitrate circulation, with less nitrate influx to leaves under low K availablity combined with waterlogging and more isotopic dilution of lamina nitrates under high K. Our results show that K deficiency and waterlogging effects are not simply additive, reshape respiration as well as nitrogen metabolism and partitioning, and are associated with metabolomic and isotopic biomarkers of potential interest for crop monitoring. 10.1111/pce.13450
    Comparative Transcriptome Combined with Proteome Analyses Revealed Key Factors Involved in Alfalfa () Response to Waterlogging Stress. Zeng Ningbo,Yang Zhijian,Zhang Zhifei,Hu Longxing,Chen Liang International journal of molecular sciences Alfalfa () is the most widely grown and most important forage crop in the world. However, alfalfa is susceptible to waterlogging stress, which is the major constraint for its cultivation area and crop production. So far, the molecular mechanism of alfalfa response to the waterlogging is largely unknown. Here, comparative transcriptome combined with proteomic analyses of two cultivars (M12, tolerant; M25, sensitive) of alfalfa showing contrasting tolerance to waterlogging were performed to understand the mechanism of alfalfa in response to waterlogging stress. Totally, 748 (581 up- and 167 down-regulated) genes were differentially expressed in leaves of waterlogging-stressed alfalfa compared with the control (M12_W vs. M12_CK), whereas 1193 (740 up- and 453 down-regulated) differentially abundant transcripts (DATs) were detected in the leaves of waterlogging-stressed plants in comparison with the control plants (M25_W vs. M25_CK). Furthermore, a total of 187 (122 up- and 65 down-regulated) and 190 (105 up- and 85 down-regulated) differentially abundant proteins (DAPs) were identified via isobaric tags for relative and absolute quantification (iTRAQ) method in M12_W vs. M12_CK and M25_W vs. M25_CK comparison, respectively. Compared dataset analysis of proteomics and transcriptomics revealed that 27 and eight genes displayed jointly up-regulated or down-regulated expression profiles at both mRNA and protein levels in M12_W vs. M12_CK comparison, whereas 30 and 27 genes were found to be co-up-regulated or co-down-regulated in M25_W vs. M25_CK comparison, respectively. The strongly enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways for co-up-regulated genes at mRNA and protein levels in M12_W vs. M12_CK comparison were 'Amino sugar and nucleotide sugar metabolism', 'Arginine and proline metabolism' and 'Starch and sucrose metabolism', whereas co-up-regulated protein-related pathways including 'Arginine and proline metabolism' and 'Valine, leucine and isoleucine degradation' were largely enriched in M25_W vs. M25_CK comparison. Importantly, the identified genes related to beta-amylase, Ethylene response Factor (ERF), Calcineurin B-like (CBL) interacting protein kinases (CIPKs), Glutathione peroxidase (GPX), and Glutathione-S-transferase (GST) may play key roles in conferring alfalfa tolerance to waterlogging stress. The present study may contribute to our understanding the molecular mechanism underlying the responses of alfalfa to waterlogging stress, and also provide important clues for further study and in-depth characterization of waterlogging-resistance breeding candidate genes in alfalfa. 10.3390/ijms20061359
    Transcriptomic and anatomic profiling reveal the germination process of different wheat varieties in response to waterlogging stress. Shen Changwei,Yuan Jingping,Qiao Hong,Wang Zijuan,Liu Yuanhai,Ren Xiujuan,Wang Fei,Liu Xing,Zhang Ying,Chen Xiling,Ou Xingqi BMC genetics BACKGROUND:Waterlogging is one of the most serious abiotic stresses affecting wheat-growing regions in China. Considerable differences in waterlogging tolerance have been found among different wheat varieties, and the mechanisms governing the waterlogging tolerance of wheat seeds during germination have not been elucidated. RESULTS:The results showed no significant difference between the germination rate of 'Bainong 207' (BN207) (after 72 h of waterlogging treatment) and that of the control seeds. However, the degree of emulsification and the degradation rate of endosperm cells under waterlogging stress were higher than those obtained with the control treatment, and the number of amyloplasts in the endosperm was significantly reduced by waterlogging. Transcriptomic data were obtained from seed samples (a total of 18 samples) of three wheat varieties, 'Zhoumai 22' (ZM22), BN207 and 'Bainong 607' (BN607), subjected to the waterlogging and control treatments. A comprehensive analysis identified a total of 2775 differentially expressed genes (DEGs). In addition, an analysis of the correlations among the expression difference levels of DEGs and the seed germination rates of the three wheat varieties under waterlogging stress revealed that the relative expression levels of 563 and 398 genes were positively and negatively correlated with the germination rate of the wheat seeds, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that the difference in the waterlogging tolerance among the three wheat varieties was related to the abundance of key genes involved in the glycolysis pathway, the starch and sucrose metabolism pathway, and the lactose metabolism pathway. The alcohol dehydrogenase (ADH) gene in the endosperm of BN607 was induced immediately after short-term waterlogging, and the energy provided by the glycolysis pathway enabled the BN607 seeds to germinate as early as possible; in addition, the expression of the AP2/ERF transcription factor was upregulated to further enhance the waterlogging tolerance of this cultivar. CONCLUSIONS:Taken together, the results of this study help elucidate the mechanisms through which different wheat varieties respond to waterlogging stress during germination. 10.1186/s12863-020-00901-y
    A group VII ethylene response factor gene, ZmEREB180, coordinates waterlogging tolerance in maize seedlings. Yu Feng,Liang Kun,Fang Tian,Zhao Hailiang,Han Xuesong,Cai Manjun,Qiu Fazhan Plant biotechnology journal Group VII ethylene response factors (ERFVIIs) play important roles in ethylene signalling and plant responses to flooding. However, natural ERFVII variations in maize (ZmERFVIIs) that are directly associated with waterlogging tolerance have not been reported. Here, a candidate gene association analysis of the ZmERFVII gene family showed that a waterlogging-responsive gene, ZmEREB180, was tightly associated with waterlogging tolerance. ZmEREB180 expression specifically responded to waterlogging and was up-regulated by ethylene; in addition, its gene product localized to the nucleus. Variations in the 5'-untranslated region (5'-UTR) and mRNA abundance of this gene under waterlogging conditions were significantly associated with survival rate (SR). Ectopic expression of ZmEREB180 in Arabidopsis increased the SR after submergence stress, and overexpression of ZmEREB180 in maize also enhanced the SR after long-term waterlogging stress, apparently through enhanced formation of adventitious roots (ARs) and regulation of antioxidant levels. Transcriptomic assays of the transgenic maize line under normal and waterlogged conditions further provided evidence that ZmEREB180 regulated AR development and reactive oxygen species homeostasis. Our study provides direct evidence that a ZmERFVII gene is involved in waterlogging tolerance. These findings could be applied directly to breed waterlogging-tolerant maize cultivars and improve our understanding of waterlogging stress. 10.1111/pbi.13140
    Elevated temperature and waterlogging decrease cottonseed quality by altering the accumulation and distribution of carbohydrates, oil and protein. Xu Bingjie,Chen Yinglong,Wang Haimiao,Zhao Wenqing,Zhou Zhiguo Physiologia plantarum Soil waterlogging and high-temperature events have occurred simultaneously in recent years in the Yangtze River basin cotton belt region of China, negatively affecting the development and quality of cottonseed. This study investigated the effects of the combination of elevated temperature (ET) (34.1/29.0°C) and waterlogging (3 or 6 days) on the accumulation and distribution of oil, protein and carbohydrates in cottonseed during flowering and boll development. The results showed that ET resulted in greater decreases in cottonseed biomass under waterlogging than under control conditions. The combination of waterlogging and ET significantly limited the accumulation of carbohydrates and oil contents. However, ET promoted protein accumulation and compensated for the negative effects of 3-day waterlogging on the final protein content. The combined ET and 6-day waterlogging significantly decreased the final contents of oil and protein by limiting carbon flux and NADPH supply because of the decreased activities of phosphoenolpyruvate carboxylase (PEPC, EC and glucose-6-phosphate dehydrogenase (G6PDH, EC The PEPC activity was correlated more with protein content than oil content. In addition, simultaneous exposure to waterlogging and ET resulted in lower unsaturated fatty acid/saturated fatty acid ratios and essential amino acid/non-essential amino acid ratios than did exposure to the individual factors alone. These findings could provide the theoretical support for the prospective assessment of effects of high temperature and waterlogging stresses on cotton production under climate change, and they can help to develop effective techniques in cotton cultivation. 10.1111/ppl.13213
    Genome-Wide Analysis of Gene Expression Provides New Insights into Waterlogging Responses in Barley ( L.). Borrego-Benjumea Ana,Carter Adam,Tucker James R,Yao Zhen,Xu Wayne,Badea Ana Plants (Basel, Switzerland) Waterlogging is a major abiotic stress causing oxygen depletion and carbon dioxide accumulation in the rhizosphere. Barley is more susceptible to waterlogging stress than other cereals. To gain a better understanding, the genome-wide gene expression responses in roots of waterlogged barley seedlings of Yerong and Deder2 were analyzed by RNA-Sequencing. A total of 6736, 5482, and 4538 differentially expressed genes (DEGs) were identified in waterlogged roots of Yerong at 72 h and Deder2 at 72 and 120 h, respectively, compared with the non-waterlogged control. Gene Ontology (GO) enrichment analyses showed that the most significant changes in GO terms, resulted from these DEGs observed under waterlogging stress, were related to primary and secondary metabolism, regulation, and oxygen carrier activity. In addition, more than 297 transcription factors, including members of MYB, AP2/EREBP, NAC, WRKY, bHLH, bZIP, and G2-like families, were identified as waterlogging responsive. Tentative important contributors to waterlogging tolerance in Deder2 might be the highest up-regulated DEGs: Trichome birefringence, α/β-Hydrolases, Xylanase inhibitor, MATE efflux, serine carboxypeptidase, and SAUR-like auxin-responsive protein. The study provides insights into the molecular mechanisms underlying the response to waterlogging in barley, which will be of benefit for future studies of molecular responses to waterlogging and will greatly assist barley genetic research and breeding. 10.3390/plants9020240
    Spraying 6-BA could alleviate the harmful impacts of waterlogging on dry matter accumulation and grain yield of wheat. Wang Xiaoyan,Liu Daoming,Wei Mingmei,Man Jianguo PeerJ Background:The middle and lower reaches of the Yangtze River plain produce the second highest amount of wheat in China; however, waterlogging is an important environmental factor that substantially affects the yield production of wheat ( L.) in this region. Methods:In this study, seven treatments were implemented, including no waterlogging and exogenous 6-benzylaminopurine (6-BA) as a control (CK); waterlogging at booting (BW), anthesis (AW) and 15 days after anthesis (DAA, FW); and spraying 6-BA before waterlogging at booting (BW-6BA), anthesis (AW-6BA) and 15 DAA (FW-6BA), to determine the ability of 6-BA to alleviate the harmful impact of waterlogging on aboveground biomass production and grain yield. The widely cultivated wheat cultivar "Zhengmai 9023" was used. Results:The results showed that more than 190.0 mm of rainfall, which accounted for approximately 45.0% of the precipitation over the whole wheat growing season, was distributed after the booting stage (April and May). In all waterlogged treatments, the photosynthetic rate, aboveground biomass and grain yield decreased, but the differences between the CK and the FW treatment were not significant. The grain yield decreased by 18.38%, 41.79% and 5.67% in the BW, AW and FW treatments, respectively. Spraying 6-BA before waterlogging enhanced the root activities after anthesis and then decreased the malondialdehyde concentrations of the flag leaves and the third leaf, increased the photosynthetic rate of the flag leaves and enhanced aboveground biomass and grain yield. Among the increments between the treatments, the increments between the BW and BW-6BA treatments were the largest, but between the FW and FW-6BA were smallest. In comparison to the other waterlogging treatments, the grain yields from the FW and FW-6BA treatments were significantly higher because of the higher kernel numbers per spike. The results indicated that waterlogging after the booting stage restrained the dry matter production of winter wheat, but spraying 6-BA before waterlogging slowed the plant senescence rate and reduced grain yield loss. 10.7717/peerj.8193
    Overexpression of Barley Transcription Factor in Enhances Plant Waterlogging Tolerance. Luan Haiye,Guo Baojian,Shen Huiquan,Pan Yuhan,Hong Yi,Lv Chao,Xu Rugen International journal of molecular sciences Waterlogging stress significantly affects the growth, development, and productivity of crop plants. However, manipulation of gene expression to enhance waterlogging tolerance is very limited. In this study, we identified an ethylene-responsive factor from barley, which was strongly induced by waterlogging stress. This transcription factor named was 1158 bp in length and encoded 385 amino acids, and mainly expressed in the adventitious root and seminal root. Overexpression of in led to enhanced tolerance to waterlogging stress. Further analysis of the transgenic plants showed that the expression of , and increased rapidly, while the same genes did not do so in non-transgenic plants, under waterlogging stress. Activities of antioxidant enzymes and alcohol dehydrogenase (ADH) were also significantly higher in the transgenic plants than in the non-transgenic plants under waterlogging stress. Therefore, these results indicate that plays a positive regulatory role in plant waterlogging tolerance through regulation of waterlogging-related genes, improving antioxidant and ADH enzymes activities. 10.3390/ijms21061982
    Root length is proxy for high-throughput screening of waterlogging tolerance in Urochloa spp. grasses. de la Cruz Jiménez Juan,Cardoso Juan A,Kotula Lukasz,Veneklaas Erik J,Pedersen Ole,Colmer Timothy D Functional plant biology : FPB C4 perennial Urochloa spp. grasses are widely planted in extensive areas in the tropics. These areas are continuously facing waterlogging events, which limits plant growth and production. However, no commercial cultivar combining excellent waterlogging tolerance with superior biomass production and nutritional quality is available. The objective of this study was to identify root traits that can be used for selecting waterlogging tolerant species of Urochloa. Root respiration, root morphological, architectural and anatomical traits were evaluated in eight contrasting Urochloa spp. genotypes grown under aerated or deoxygenated stagnant solutions. Moreover, modelling of internal aeration was used to relate differences in root traits and root growth in waterlogged soils. Increased aerenchyma formation in roots, reduced stele area and development of a fully suberised exodermis are characteristics improving internal aeration of roots and therefore determining waterlogging tolerance in these C4 forage grasses. Waterlogging-tolerant genotypes had steeper root angles and greater root lengths than the waterlogging-sensitive genotypes. In stagnant conditions, waterlogging-tolerant genotypes had a greater proportion of aerenchyma and reduced stele area in root cross-sections, had deeper roots, steeper root angle and larger root biomass, which in turn, allowed for greater shoot biomass. Total root length had the strongest positive influence on shoot dry mass and can therefore be used as proxy for selecting waterlogging tolerant Urochloa genotypes. 10.1071/FP20200
    Different Waterlogging Depths Affect Spatial Distribution of Fine Root Growth for Seedlings. Fujita Saki,Noguchi Kyotaro,Tange Takeshi Frontiers in plant science The increase of waterlogged environments at forests and urban greenery is of recent concern with the progress of climate change. Under waterlogging, plant roots are exposed to hypoxic conditions, which strongly affect root growth and function. However, its impact is dependent on various factors, such as waterlogging depth. Therefore, our objective is to elucidate effects of different waterlogging depths on Parl., which is widely used for afforestation, especially at coastal forests. We conducted an experiment to examine growth and morphology of fine roots and transpiration using 2-year-old seedlings under three treatments, (1) control (no waterlogging), (2) partial waterlogging (partial-WL, waterlogging depth = 15 cm from the bottom), and (3) full waterlogging (full-WL, waterlogging depth = from the bottom to the soil surface, 26 cm). As a result, fine root growth and transpiration were both significantly decreased at full-WL. However, for partial-WL, fine root growth was significantly increased compared to control and full-WL at the top soil, where it was not waterlogged. Additionally, transpiration which had decreased after 4 weeks of waterlogging showed no significant difference compared to control after 8 weeks of waterlogging. This recovery is to be attributed to the increase in fine root growth at non-waterlogged top soil, which compensated for the damaged roots at the waterlogged bottom soil. In conclusion, this study suggests that is sensitive to waterlogging; however, it can adapt to waterlogging by plastically changing the distribution of fine root growth. 10.3389/fpls.2021.614764
    The presence of moderate salt can increase tolerance of seedlings to waterlogging stress. Liu Xiaojuan,Chen Chunxiao,Liu Yun,Liu Yanlu,Zhao Yang,Chen Min Plant signaling & behavior High salinity and waterlogging are two stress factors that often occur simultaneously in nature, particularly during the rainy season in the Yellow River Delta (YRD) of China. An attractive approach to improve the saline-alkali soil produced by waterlogging and high salt is to use plants for wetland ecosystem restoration. In this work, we examined the ecological adaptability of L. under combined waterlogging and salt stress, to evaluate the potential of this species for introduction to the YRD. We monitored the effects of salt plus waterlogging co-stress on the anatomy, physiology, and enzymatic systems in seedlings. Salt alone and waterlogging alone inhibited the growth of the seedlings, while salt plus waterlogging co-stress reduced this growth inhibition. Furthermore, seedlings resisted the salt plus waterlogging co-stress by increasing porosity, accumulating more inorganic ions and organic solutes, and increasing antioxidant enzyme activities to maintain high photosynthetic rates and membrane stability and thus avoid damage. These findings support the inclusion of in the ecological restoration of the YRD. 10.1080/15592324.2020.1743518
    Foliar Glycine Betaine or Hydrogen Peroxide Sprays Ameliorate Waterlogging Stress in Cape Gooseberry. Castro-Duque Nicolas E,Chávez-Arias Cristhian C,Restrepo-Díaz Hermann Plants (Basel, Switzerland) Exogenous glycine betaine (GB) or hydrogen peroxide (HO) application has not been explored to mitigate waterlogging stress in Andean fruit trees. The objective of this study was to evaluate foliar GB or HO application on the physiological behavior of Cape gooseberry plants under waterlogging. Two separate experiments were carried out. In the first trial, the treatment groups were: (1) plants without waterlogging and with no foliar applications, (2) plants with waterlogging and without foliar applications, and (3) waterlogged plants with 25, 50, or 100 mM of HO or GB, respectively. The treatments in the second trial were: (1) plants without waterlogging and with no foliar applications, (2) plants with waterlogging and without foliar applications, and (3) waterlogged plants with 100 mM of HO or GB, respectively. In the first experiment, plants with waterlogging and with exogenous GB or HO applications at a dose of 100 mM showed higher leaf water potential (-0.5 Mpa), dry weight (1.0 g), and stomatal conductance (95 mmol·m·s) values. In the second experiment, exogenously supplied GB or HO also increased the relative growth rate, and leaf photosynthesis mitigating waterlogging stress. These results show that short-term GB or HO supply can be a tool in managing waterlogging in Cape gooseberry. 10.3390/plants9050644
    [Research progress of the response mechanism of wheat growth to waterlogging stress and the related regulating managements.] Gao Jing-Wen,Su Yao,Shen A-Lin Ying yong sheng tai xue bao = The journal of applied ecology The frequency of waterlogging events is increasing in recent years due to climate change. Wheat, a dryland crop, is particularly sensitive to waterlogging. Moreover, waterlogging stress is especially serious in the main wheat-producing regions at the middle and lower reaches of the Yangtze River as influenced by regional climate, soil, rotating system and other factors. Oxygen content in soil decreases under waterlogging condition, which inhibits root growth, restricts plant growth, and eventually reduces wheat yield and grain quality. In the present study, we reviewed the current national and international research progress in the underlying physiological mechanisms of inhibitory wheat growth by waterlogging stress, from the aspects of root respiration, water transport, mineral nutrient absorption, photosynthesis, redox metabolism. We discussed the physiological adaptions of wheat to waterlogging, including maintaining energy supply through anaerobic respiration and oxygen supply through changes of root morphology. We listed the application of cultivation measures such as fertilizer regulation, growth regulator regulation and stress memory in improving waterlogging stress-tolerance in wheat with the underlying physiological mechanisms summarized. We also prospected the future study on waterlogging stress-tolerance in wheat, aiming to provide theoretical foundation for waterlogging-tolerant cultivation and maintaining high yield of wheat. 10.13287/j.1001-9332.202012.028
    Hydrogen Sulfide Alleviates Waterlogging-Induced Damage in Peach Seedlings via Enhancing Antioxidative System and Inhibiting Ethylene Synthesis. Xiao Yuansong,Wu Xuelian,Sun Maoxiang,Peng Futian Frontiers in plant science Peach ( L. Batsch) is a shallow root fruit tree with poor waterlogging tolerance. Hydrogen sulfide (HS) is a signal molecule which regulates the adaptation of plants to adverse environments. Nevertheless, the effects of exogenous applications of HS in fruit tree species especially in peach trees under waterlogging stress have been scarcely researched. Thus, the goal of this research was to investigate the alleviating effect of exogenous HS on peach seedlings under waterlogging stress. In the present study, we found that the effect of exogenous HS depended on the concentration and 0.2 mM sodium hydrosulfide (NaHS) showed the best remission effect on peach seedlings under waterlogging stress. Waterlogging significantly reduced the stomatal opening, net photosynthetic rate, and Fv/Fm of peach seedlings. The results of histochemical staining and physiological and biochemical tests showed that waterlogging stress increased the number of cell deaths and amounts of reactive oxygen species (ROS) accumulated in leaves, increased the number of root cell deaths, significantly increased the electrolyte permeability, O. production rate, HO content and ethylene synthesis rate of roots, and significantly reduced root activity. With prolonged stress, antioxidative enzyme activity increased initially and then decreased. Under waterlogging stress, application of 0.2 mM NaHS increased the number of stomatal openings, improved the chlorophyll content, and photosynthetic capacity of peach seedlings. Exogenous HS enhanced antioxidative system and significantly alleviate cell death of roots and leaves of peach seedlings caused by waterlogging stress through reducing ROS accumulation in roots and leaves. HS can improve the activity and proline content of roots, reduce oxidative damage, alleviated lipid peroxidation, and inhibit ethylene synthesis. The HS scavenger hypotaurine partially eliminated the effect of exogenous HS on alleviating waterlogging stress of peach seedlings. Collectively, our results provide an insight into the protective role of HS in waterlogging-stressed peach seedlings and suggest HS as a potential candidate in reducing waterlogging-induced damage in peach seedlings. 10.3389/fpls.2020.00696
    Potassium Alleviates Post-anthesis Photosynthetic Reductions in Winter Wheat Caused by Waterlogging at the Stem Elongation Stage. Gao Jingwen,Su Yao,Yu Man,Huang Yiqian,Wang Feng,Shen Alin Frontiers in plant science Waterlogging occurs frequently at the stem elongation stage of wheat in southern China, decreasing post-anthesis photosynthetic rates and constraining grain filling. This phenomenon, and the mitigating effect of nutrient application, should be investigated as it could lead to improved agronomic guidelines. We exposed pot-cultured wheat plants at the stem elongation stage to waterlogging treatment in combination with two rates of potassium (K) application. Waterlogging treatment resulted in grain yield losses, which we attributed to a reduction in the 1,000-grain weight caused by an early decline in the net photosynthetic rate (Pn) post-anthesis. These decreases were offset by increasing K application. Stomatal conductance ( ) and the intercellular CO concentration ( ) decreased in the period 7-21 days after anthesis (DAA), and these reductions were exacerbated by waterlogging. However, in the period 21-28 DAA, and increased, while Pn decreased continuously, suggesting that non-stomatal factors constrained photosynthesis. On DAA 21, Pn was reduced by waterlogging, but photochemical efficiency (Φ ) remained unchanged, indicating a reduction in the dissipation of energy captured by photosystem II (PSII) through the CO assimilation pathway. This reduction in energy dissipation increased the risk of photodamage, as shown by early reductions in Φ in waterlogged plants on DAA 28. However, increased K application promoted root growth and nutrient status under waterlogging, thereby improving photosynthesis post-anthesis. In conclusion, the decrease in Pn caused by waterlogging was attributable to stomatal closure during early senescence; during later senescence, a reduction in CO assimilation accounted for the reduced Pn and elevated the risk of photodamage. However, K application mitigated waterlogging-accelerated photosynthetic reductions and reduced yield losses. 10.3389/fpls.2020.607475
    How Does the Waterlogging Regime Affect Crop Yield? A Global Meta-Analysis. Tian Li-Xin,Zhang Yu-Chuan,Chen Peng-Liang,Zhang Fei-Fei,Li Jing,Yan Feng,Dong Yang,Feng Bai-Li Frontiers in plant science Waterlogging, an abiotic stress, severely restricts crop yield in various parts of the world. Thus, we conducted a meta-analysis of 2,419 comparisons from 115 studies to comprehensively evaluate the overall change in crop yield induced by waterlogging in the global region. The results suggested that waterlogging obviously decreased crop yield by 32.9% on average, compared with no waterlogging, which was a result of a reduced 1,000-grain weight (13.67%), biomass (28.89%), plant height (10.68%), net photosynthetic rate ( , 39.04%), and leaf area index (LAI, 22.89%). The overall effect of a waterlogging regime on crop yield is related to the crop type; the crop yield reduction varied between wheat (25.53%) and cotton (59.95%), with an overall average value of 36.81% under field conditions. In addition, we also found that compared with no waterlogging, waterlogging in the reproductive growth stage (41.90%) caused a greater yield reduction than in the vegetative growth stage (34.75%). Furthermore, decreases in crop yield were observed with an extension in the waterlogging duration; the greatest decreases in crop yield occurred at 15 < D ≤ 28 (53.19 and 55.96%) under field and potted conditions, respectively. Overall, the results of this meta-analysis showed that waterlogging can decrease crop yield and was mainly affected by crop type, growth stage, and experimental duration. 10.3389/fpls.2021.634898
    Short-term waterlogging-induced autophagy in root cells of wheat can inhibit programmed cell death. Zhou Li-Lang,Gao Kai-Yue,Cheng Li-Sha,Wang Yue-Li,Cheng Yi-Keng,Xu Qiu-Tao,Deng Xiang-Yi,Li Ji-Wei,Mei Fang-Zhu,Zhou Zhu-Qing Protoplasma Autophagy is a pathway for the degradation of cytoplasmic components in eukaryotes. In wheat, the mechanism by which autophagy regulates programmed cell death (PCD) is unknown. Here, we demonstrated that short-term waterlogging-induced autophagy inhibited PCD in root cells of wheat. The waterlogging-tolerant wheat cultivar Huamai 8 and the waterlogging-sensitive wheat cultivar Huamai 9 were used as experimental materials, and their roots were waterlogged for 0-48 h. Waterlogging stress increased the number of autophagic structures, the expression levels of autophagy-related genes (TaATG), and the occurrence of PCD in root cells. PCD manifested as morphological changes in the cell nucleus, significant enhancement of DNA laddering bands, and increases in caspase-like protease activity and the expression levels of metacaspase genes. The autophagy promoter rapamycin (RAPA) reduced PCD levels, whereas the autophagy inhibitor 3-methyladenine (3-MA) enhanced them. The expression levels of TaATG genes and the number of autophagic structures were lower in cortex cells than in stele cells, but the levels of PCD were higher in cortex cells. The number of autophagic structures was greater in Huamai 8 than in Huamai 9, but the levels of PCD were lower. In summary, our results showed that short-term waterlogging induced autophagy which could inhibit PCD. Mechanisms of response to waterlogging stress differed between cortex and stele cells and between two wheat cultivars of contrasting waterlogging tolerance. 10.1007/s00709-021-01610-8
    Long-Term Waterlogging as Factor Contributing to Hypoxia Stress Tolerance Enhancement in Cucumber: Comparative Transcriptome Analysis of Waterlogging Sensitive and Tolerant Accessions. Kęska Kinga,Szcześniak Michał Wojciech,Makałowska Izabela,Czernicka Małgorzata Genes Waterlogging (WL), excess water in the soil, is a phenomenon often occurring during plant cultivation causing low oxygen levels (hypoxia) in the soil. The aim of this study was to identify candidate genes involved in long-term waterlogging tolerance in cucumber using RNA sequencing. Here, we also determined how waterlogging pre-treatment (priming) influenced long-term memory in WL tolerant (WL-T) and WL sensitive (WL-S) i.e., DH2 and DH4 accessions, respectively. This work uncovered various differentially expressed genes (DEGs) activated in the long-term recovery in both accessions. De novo assembly generated 36,712 transcripts with an average length of 2236 bp. The results revealed that long-term waterlogging had divergent impacts on gene expression in WL-T DH2 and WL-S DH4 cucumber accessions: after 7 days of waterlogging, more DEGs in comparison to control conditions were identified in WL-S DH4 (8927) than in WL-T DH2 (5957). Additionally, 11,619 and 5007 DEGs were identified after a second waterlogging treatment in the WL-S and WL-T accessions, respectively. We identified genes associated with WL in cucumber that were especially related to enhanced glycolysis, adventitious roots development, and amino acid metabolism. qRT-PCR assay for hypoxia marker genes i.e., (), () and () confirmed differences in response to waterlogging stress between sensitive and tolerant cucumbers and effectiveness of priming to enhance stress tolerance. 10.3390/genes12020189