scholarly journals Transcriptional Regulation of Hydrogen Peroxide and Calcium for Signaling Transduction and Stress-defensive Genes Contributing to Improved Drought Tolerance in Creeping Bentgrass

2020 ◽  
Vol 145 (4) ◽  
pp. 236-246
Author(s):  
Zhou Li ◽  
Yan Peng ◽  
Bingru Huang
Keyword(s):  
Transcription Factors ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Creeping Bentgrass ◽  
Grass Species ◽  
Regulation Of Transcription ◽  
Signaling Transduction ◽  
Genes Expression ◽  
Protective Genes ◽  
Ca Signaling

Small molecules, including H2O2 and Ca, mediate stress signaling and drought tolerance in plants. The objective of this study was to determine whether improvement in drought tolerance by H2O2 and Ca were associated with the regulation of transcription factors and stress-protective genes in perennial grass species. Plants of creeping bentgrass (Agrostis stolonifera) were sprayed with water (control), H2O2 (9 mm), or CaCl2 (10 mm) and exposed to drought stress for 20 days in controlled-environment growth chambers. Foliar application of H2O2 or Ca led to significant improvement in drought tolerance of creeping bentgrass, as demonstrated by greater turf quality, leaf relative water content, chlorophyll content, photochemical efficiency, and cell membrane stability, as compared with the untreated control. The application of H2O2 and Ca resulted in significant up-regulation of genes in Ca signaling transduction pathways [Ca-dependent kinase 26 (CDPK26), mitogen-activated protein kinase 1 (MAPK1), and 14-3-3] and transcript factors (WRKY75 and MYB13). For genes encoding antioxidant enzymes, H2O2 mainly enhanced superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and dehydroascorbate reductase (DHAR) expression, while Ca primarily improved transcript levels of SOD, monodehydroascorbate reductase (MDHAR), and GR. In addition, heat shock protein 70 (HSP70), metallothionein 1 (MT1), and glutamine synthetase 2 (GS2) were also markedly up-regulated by H2O2 and Ca under drought stress. However, the transcript level of lipoxygenase 3 (LOX3) was significantly down-regulated by H2O2 and Ca under well-watered and drought conditions. These results imply that H2O2 and Ca commonly or differentially regulate genes expression in association with drought tolerance through activating Ca signaling pathway and regulating transcription factors and stress-protective genes expression, leading to the alleviation of lipid peroxidation, maintenance of correct protein folding and translocation, and enhancement of nitrogen metabolism under a prolonged period of drought stress in creeping bentgrass.

Expression changes in the TaNAC2 and TaNAC69-1 transcription factors in drought stress tolerant and susceptible accessions of Triticum boeoticum

2019 ◽  
Vol 17 (6) ◽  
pp. 471-479 ◽  
Author(s):  
Maryam Nazari ◽  
Kiarash Jamshidi Goharrizi ◽  
Sayyed Saeed Moosavi ◽  
Mahmood Maleki
Keyword(s):  
Transcription Factors ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Molecular Level ◽  
Stress Conditions ◽  
Wild Wheat ◽  
Genes Expression ◽  
Adaptive Mechanisms ◽  
Triticum Boeoticum ◽  
Modern Wheat

AbstractTriticum boeoticum is a valuable gene source for tolerance to drought stress. In order to study the effect of drought stress on this plant, and to understand its adaptive mechanisms at the molecular level, 10 accessions of T. boeoticum were evaluated under non- and drought stress conditions. Evaluation of 31 different phenological, morpho-physiological and root-related traits showed that there were significant differences between accessions. Using the bi-plot resulting from the PCA, the studied traits and accessions were separated in different groups. The most tolerant (B5) and susceptible (B6) accessions to drought stress were identified, so these accessions were used for assessment of changes in the TaNAC2 and TaNAC69-1 transcription factors (TFs) expression. The results showed that in the most tolerant and susceptible accessions, TaNAC2 and TaNAC69-1 expression levels increased between non-stress and stress conditions significantly, but the increased level of these two genes expression in the most tolerant accession was much higher than the most susceptible accession. According to the obtained results, T. boeoticum can be a suitable and promising gene source for improving modern wheat. In addition, the results of TFs expression could improve our understanding about the complex mechanisms associated with drought tolerance in wheat, especially wild wheat.

scholarly journals Leaf Protein Abundance Associated with Improved Drought Tolerance by Elevated Carbon Dioxide in Creeping Bentgrass

2016 ◽  
Vol 141 (1) ◽  
pp. 85-96 ◽  
Author(s):  
Patrick Burgess ◽  
Bingru Huang
Keyword(s):  
Drought Stress ◽  
Carbon Fixation ◽  
Creeping Bentgrass ◽  
Grass Species ◽  
Leaf Water Content ◽  
Protein Abundance ◽  
Respiratory Metabolism ◽  
Plant Tolerance ◽  
Bisphosphate Carboxylase ◽  
Atp Production

Elevated CO2 may contribute toward plant tolerance to prolonged drought stress. The objective of this study was to investigate changes in protein abundance associated with mitigation of drought stress by elevated CO2 in leaves of a cool-season grass species used as fine turfgrass. Plants of creeping bentgrass (Agrostis stolonifera cv. Penncross) were grown at either ambient CO2 concentration (400 µL·L−1) or elevated CO2 concentration (800 µL·L−1) for 35 days under well-irrigated and fertilized conditions and then subjected to drought stress for 21 days by withholding irrigation. Plants exposed to elevated CO2 concentration maintained higher leaf water content, membrane stability, and visual turf quality (TQ) under drought stress compared with plants grown under ambient CO2 conditions. The abundance of proteins involved in photosynthetic carbon fixation and assimilation, including chloroplastic glyceraldehyde phosphate dehydrogenase A (GAPDH-A) and ribulose 1,5-bisphosphate carboxylase (RuBisCO) decreased less and the abundance of proteins involved in respiratory metabolism (i.e., cytosolic GAPDH) increased less during drought due to elevated CO2. The results suggest that elevated CO2 lessened growth and physiological damages during drought by facilitating ribulose 1,5-bisphosphate regeneration and adenosine triphosphate (ATP) production in photosynthesis and downregulating factors contributing to respiratory metabolism.

scholarly journals Transcriptome Analysis Revealed GhWOX4 Intercedes Myriad Regulatory Pathways to Modulate Drought Tolerance and Vascular Growth in Cotton

2021 ◽  
Vol 22 (2) ◽  
pp. 898
Author(s):  
Muhammad Sajjad ◽  
Xi Wei ◽  
Lisen Liu ◽  
Fuguang Li ◽  
Xiaoyang Ge
Keyword(s):  
Transcription Factors ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Plant Growth ◽  
Growth And Development ◽  
Differentially Expressed ◽  
Growth And Yield ◽  
Regulatory Pathways ◽  
Vascular Growth

Cotton is a paramount cash crop around the globe. Among all abiotic stresses, drought is a leading cause of cotton growth and yield loss. However, the molecular link between drought stress and vascular growth and development is relatively uncharted. Here, we validated a crucial role of GhWOX4, a transcription factor, modulating drought stress with that of vasculature growth in cotton. Knock-down of GhWOX4 decreased the stem width and severely compromised vascular growth and drought tolerance. Conversely, ectopic expression of GhWOX4 in Arabidopsis enhanced the tolerance to drought stress. Comparative RNAseq analysis revealed auxin responsive protein (AUX/IAA), abscisic acid (ABA), and ethylene were significantly induced. Additionally, MYC-bHLH, WRKY, MYB, homeodomain, and heat-shock transcription factors (HSF) were differentially expressed in control plants as compared to GhWOX4-silenced plants. The promotor zone of GhWOX4 was found congested with plant growth, light, and stress response related cis-elements. differentially expressed genes (DEGs) related to stress, water deprivation, and desiccation response were repressed in drought treated GhWOX4-virus-induced gene silencing (VIGS) plants as compared to control. Gene ontology (GO) functions related to cell proliferation, light response, fluid transport, and flavonoid biosynthesis were over-induced in TRV: 156-0 h/TRV: 156-1 h (control) in comparison to TRV: VIGS-0 h/TRV: VIGS-1 h (GhWOX4-silenced) plants. This study improves our context for elucidating the pivotal role of GhWOX4 transcription factors (TF), which mediates drought tolerance, plays a decisive role in plant growth and development, and is likely involved in different regulatory pathways in cotton.

Seed-germination response of Leymus chinensis to cold stratification in a range of temperatures, light and low water potentials under salt and drought stresses

2017 ◽  
Vol 68 (2) ◽  
pp. 188 ◽  
Author(s):  
Jixiang Lin ◽  
Yujie Shi ◽  
Shuang Tao ◽  
Xingyang Yu ◽  
Dafu Yu ◽  
...  
Keyword(s):  
Drought Stress ◽  
Seed Germination ◽  
Drought Tolerance ◽  
Northeast China ◽  
Germination Percentage ◽  
Leymus Chinensis ◽  
Grass Species ◽  
Cold Stratification ◽  
Effective Measure ◽  
Salt And Drought Stresses

Leymus chinensis has important forage value and is considered a useful grass species for grassland restoration in Northeast China. However, little information exists concerning the germination responses of this species to interactions of cold stratification, light, temperature and low water potential caused by salinity and drought. Experiments were conducted in growth chambers, and the results showed that in all conditions of light, temperature and water stresses, the germination percentages of cold-stratified seeds were higher than of non-stratified seeds. Light had an inhibitory effect on germination percentage under both non-saline and salt stress conditions; darkness is beneficial for germination of this species. In addition, seeds germinated much better under alternating temperature regimes than under constant temperatures. Both salt and drought stresses decreased the germination percentage of Leymus chinensis, but the reductions under drought stress were much greater. Moreover, after being transferred to distilled water, most non-germinated seeds under drought stress germinated well, and the total percentage reached that of the non-saline condition level. Therefore, cold stratification is an effective measure to increase seed germination and salt or drought tolerance, especially in darkness. We conclude that Leymus chinensis has definite salt and drought tolerance during the germination stage and it is a promising species for the restoration of deteriorated grassland in Northeast China.

scholarly journals Changes in Carbon Partitioning and Accumulation Patterns during Drought and Recovery for Colonial Bentgrass, Creeping Bentgrass, and Velvet Bentgrass

2006 ◽  
Vol 131 (4) ◽  
pp. 484-490 ◽  
Author(s):  
Michelle DaCosta ◽  
Bingru Huang
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Water Status ◽  
Creeping Bentgrass ◽  
Carbon Partitioning ◽  
Perennial Grasses ◽  
Species Variation ◽  
Carbohydrate Accumulation ◽  
Drought Treatment ◽  
Drought Duration

Efficient carbon distribution and utilization may enhance drought survival and recovery ability for perennial grasses. The objectives of this study were to examine changes in carbon partitioning and carbohydrate accumulation patterns in shoots and roots of colonial bentgrass (Agrostis capillaris L.), creeping bentgrass (A. stolonifera L.), and velvet bentgrass (A. canina L.) in response to drought and re-watering following drought, and to determine whether species variation in drought tolerance and recuperative potential is related to differences in the patterns of carbon partitioning and accumulation. The experiment consisted of three treatments: 1) well-watered control; 2) drought, irrigation completely withheld for 18 days; and 3) drought recovery, a group of drought-stressed plants were re-watered at the end of the drought treatment (18 days). Drought tolerance and recuperative ability of three species was evaluated by measuring turf quality and leaf relative water content. These parameters indicated that velvet bentgrass was most drought tolerant while colonial bentgrass had highest recuperative ability among the three species. Plants were labeled with 14CO2 to determine carbon partitioning to shoots and roots. Carbohydrate accumulation was assessed by total nonstructural carbohydrate (TNC) content. The proportion of newly photosynthesized 14C partitioned to roots increased at 12 days of drought compared to the pre-stress level, to a greater extent for velvet bentgrass (45%) than for colonial bentgrass (35%) and creeping bentgrass (30%). In general, the proportion of 14C was highest in roots, intermediate in stems, and lowest in leaves at 12 days of drought treatment for all three bentgrass species. As drought duration and severity increased (18 days), 14C partitioning increased more in leaves and stems relative to that in roots for all three species. Stem TNC content was significantly greater for drought-stressed plants of colonial bentgrass and velvet bentgrass compared to their respective well-watered control plants, whereas no differences in stem TNC content were observed between drought-stressed and well-watered creeping bentgrass. Our results suggest that increased carbon partitioning to roots during initial drought stress represented an adaptive response of bentgrass species to short-term drought stress, and increased carbon partitioning and carbohydrate accumulation in stems during prolonged period of drought stress could be beneficial for rapid recovery of turf growth and water status upon re-watering.

scholarly journals Evaluation of Drought Tolerance and Avoidance Traits for Six Creeping Bentgrass Cultivars

HortScience ◽  
2008 ◽  
Vol 43 (2) ◽  
pp. 519-524 ◽  
Author(s):  
Stephen E. McCann ◽  
Bingru Huang
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Water Use ◽  
Photochemical Efficiency ◽  
Creeping Bentgrass ◽  
Root Production ◽  
Drought Avoidance ◽  
Relative Water ◽  
Leaf Relative Water Content ◽  
Use Efficiency

The objectives of this study were: 1) to compare drought responses between the more recently developed creeping bentgrass cultivars to standard cultivars and 2) to determine differential drought tolerance and avoidance characteristics associated with cultivar variation in drought resistance. Six cultivars of creeping bentgrass (Agrostis stoloniferia) (‘Penn A-4’, ‘Independence’, ‘Declaration’, ‘L-93’, ‘Penncross’, and ‘Putter’) were maintained in growth chambers at 20 °C day/15 °C night either well-watered or exposed to drought stress by withholding water for 17 days. Cultivars varied in turf performance and physiological responses (leaf relative water content and photochemical efficiency) to drought stress, which was reflected in their differences in drought tolerance (osmotic adjustment) and drought avoidance traits (water use rate and efficiency, root viability, root length, and number). ‘Penn A-4,’ ‘Independence,’ and ‘L-93’ generally performed better than other three cultivars under drought conditions, mainly through maintaining higher water use efficiency, root viability, root elongation, or root production. The majority of physiological parameters evaluated suggested that of the six creeping bentgrass cultivars examined in this study, the three cultivars with better ability to survive drought stress used mainly avoidance traits related to water use and water uptake.

scholarly journals Proteins Involved in Energy Metabolism and Oxidative Regulation Associated with Genotypic Variations in Drought Tolerance for Tall Fescue

2018 ◽  
Vol 143 (3) ◽  
pp. 207-212
Author(s):  
Jianming Sun ◽  
Yiming Liu ◽  
Xianglin Li ◽  
Bingru Huang
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Tall Fescue ◽  
Photochemical Efficiency ◽  
Grass Species ◽  
Drought Treatment ◽  
Drought Tolerant ◽  
Oxidative Regulation ◽  
Tolerant Genotype ◽  
Adaptation To Drought

Protein metabolism plays an important role in plant adaptation to drought stress. The objective of this study was to identify drought-responsive proteins associated with differential drought tolerance for a tolerant genotype (RU9) and a sensitive genotype (RU18) of tall fescue (Lolium arundinacea). Plants of both genotypes were grown under well-watered conditions or subjected to drought stress by withholding irrigation for 12 days in a growth chamber controlled at the optimal growth temperatures of 23/18 °C (day/night). Physiological analysis demonstrated that RU9 was relatively more drought tolerant than RU18, as shown by the higher leaf net photosynthetic rate (Pn) and photochemical efficiency at 12 days of drought treatment. Differentially expressed proteins between RU9 and RU18 exposed to drought stress were identified by two-dimensional electrophoresis and mass spectrometry (MS). Several proteins [photosystem I reaction center subunit II, Rubisco small subunit, and Glyceraldehyde-3-phosphate dehydrogenase (GADPH)] in photosynthesis, respiration, or oxidative regulation exhibited higher abundance in RU9 than RU18 under drought stress. These results suggested the critical importance of energy and oxidative metabolism in tall fescue adaptation to drought stress. Those abundant proteins in the drought-tolerant genotype could be used as biomarkers or developed to molecular markers to develop elite drought-tolerant germplasm in tall fescue and other cool-season perennial grass species.

scholarly journals Genome-Wide Analysis of TCP Family Genes in Zea mays L. Identified a Role for ZmTCP42 in Drought Tolerance

2019 ◽  
Vol 20 (11) ◽  
pp. 2762 ◽  
Author(s):  
Shuangcheng Ding ◽  
Zhenzhen Cai ◽  
Hewei Du ◽  
Hongwei Wang
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Zea Mays L ◽  
Maize Genome ◽  
Positive Role ◽  
Maize Production ◽  
Major Constraint ◽  
Genome Wide ◽  
Genes Expression ◽  
Maize Response

The Teosinte-branched 1/Cycloidea/Proliferating (TCP) plant-specific transcription factors (TFs) have been demonstrated to play a fundamental role in plant development and organ patterning. However, it remains unknown whether or not the TCP gene family plays a role in conferring a tolerance to drought stress in maize, which is a major constraint to maize production. In this study, we identified 46 ZmTCP genes in the maize genome and systematically analyzed their phylogenetic relationships and synteny with rice, sorghum, and Arabidopsis TCP genes. Expression analysis of the 46 ZmTCP genes in different tissues and under drought conditions, suggests their involvement in maize response to drought stress. Importantly, genetic variations in ZmTCP32 and ZmTCP42 are significantly associated with drought tolerance at the seedling stage. RT-qPCR results suggest that ZmTCP32 and ZmTCP42 RNA levels are both induced by ABA, drought, and polyethylene glycol treatments. Based on the significant association between the genetic variation of ZmTCP42 and drought tolerance, and the inducible expression of ZmTCP42 by drought stress, we selected ZmTCP42, to investigate its function in drought response. We found that overexpression of ZmTCP42 in Arabidopsis led to a hypersensitivity to ABA in seed germination and enhanced drought tolerance, validating its function in drought tolerance. These results suggested that ZmTCP42 functions as an important TCP TF in maize, which plays a positive role in drought tolerance.

scholarly journals Prediction and characterization of transcription factors involved in drought stress response

2020 ◽  
Author(s):  
Chirag Gupta ◽  
Venkategowda Ramegowda ◽  
Supratim Basu ◽  
Andy Pereira
Keyword(s):  
Machine Learning ◽  
Transcription Factors ◽  
Drought Stress ◽  
Stress Response ◽  
Drought Tolerance ◽  
Web Application ◽  
Protein Structures ◽  
Gene Families ◽  
Supervised Machine Learning ◽  
Specific Gene

AbstractTranscription factors (TFs) play a central role in regulating molecular level responses of plants to external stresses such as water limiting conditions, but identification of such TFs in the genome remains a challenge. Here, we describe a network-based supervised machine learning framework that accurately predicts and ranks all TFs in the genome according to their potential association with drought tolerance. We show that top ranked regulators fall mainly into two ‘age’ groups; genes that appeared first in land plants and genes that emerged later in the Oryza clade. TFs predicted to be high in the ranking belong to specific gene families, have relatively simple intron/exon and protein structures, and functionally converge to regulate primary and secondary metabolism pathways. Repeated trials of nested cross-validation tests showed that models trained only on regulatory network patterns, inferred from large transcriptome datasets, outperform models trained on heterogenous genomic features in the prediction of known drought response regulators. A new R/Shiny based web application, called the DroughtApp, provides a primer for generation of new testable hypotheses related to regulation of drought stress response. Furthermore, to test the system we experimentally validated predictions on the functional role of the rice transcription factor OsbHLH148, using RNA sequencing of knockout mutants in response to drought stress and protein-DNA interaction assays. Our study exemplifies the integration of domain knowledge for prioritization of regulatory genes in biological pathways of well-studied agricultural traits.One Sentence SummaryNetwork-based supervised machine learning accurately predicts transcription factors involved in drought tolerance.

scholarly journals Maize WRKY Transcription Factor ZmWRKY79 Positively Regulates Drought Tolerance through Elevating ABA Biosynthesis

2021 ◽  
Vol 22 (18) ◽  
pp. 10080
Author(s):  
Faiza Gulzar ◽  
Jingye Fu ◽  
Chenying Zhu ◽  
Jie Yan ◽  
Xinglin Li ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Lateral Roots ◽  
Antioxidant Enzyme Activities ◽  
Gene Promoters ◽  
Abiotic Stress Response ◽  
Ros Scavenging ◽  
Aba Biosynthesis ◽  
Phytoalexin Biosynthesis

Drought stress causes heavy damages to crop growth and productivity under global climatic changes. Transcription factors have been extensively studied in many crops to play important roles in plant growth and defense. However, there is a scarcity of studies regarding WRKY transcription factors regulating drought responses in maize crops. Previously, ZmWRKY79 was identified as the regulator of maize phytoalexin biosynthesis with inducible expression under different elicitation. Here, we elucidated the function of ZmWRKY79 in drought stress through regulating ABA biosynthesis. The overexpression of ZmWRKY79 in Arabidopsis improved the survival rate under drought stress, which was accompanied by more lateral roots, lower stomatal aperture, and water loss. ROS scavenging was also boosted by ZmWRKY79 to result in less H2O2 and MDA accumulation and increased antioxidant enzyme activities. Further analysis detected more ABA production in ZmWRKY79 overexpression lines under drought stress, which was consistent with up-regulated ABA biosynthetic gene expression by RNA-seq analysis. ZmWRKY79 was observed to target ZmAAO3 genes in maize protoplast through acting on the specific W-boxes of the corresponding gene promoters. Virus-induced gene silencing of ZmWRKY79 in maize resulted in compromised drought tolerance with more H2O2 accumulation and weaker root system architecture. Together, this study substantiates the role of ZmWRKY79 in the drought-tolerance mechanism through regulating ABA biosynthesis, suggesting its broad functions not only as the regulator in phytoalexin biosynthesis against pathogen infection but also playing the positive role in abiotic stress response, which provides a WRKY candidate gene to improve drought tolerance for maize and other crop plants.

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