Root proteomic responses to heat stress in two Agrostis grass species contrasting in heat tolerance

Chitosan (CTS) is a deacetylated derivative of chitin that is involved in adaptive response to abiotic stresses. However, the regulatory role of CTS in heat tolerance is still not fully understood in plants, especially in grass species. The aim of this study was to investigate whether the CTS could reduce heat-induced senescence and damage to creeping bentgrass associated with alterations in antioxidant defense, chlorophyll (Chl) metabolism, and the heat shock pathway. Plants were pretreated exogenously with or without CTS (0.1 g L−1) before being exposed to normal (23/18 °C) or high-temperature (38/33 °C) conditions for 15 days. Heat stress induced detrimental effects, including declines in leaf relative water content and photochemical efficiency, but significantly increased reactive oxygen species (ROS) accumulation, membrane lipid peroxidation, and Chl loss in leaves. The exogenous application of CTS significantly alleviated heat-induced damage in creeping bentgrass leaves by ameliorating water balance, ROS scavenging, the maintenance of Chl metabolism, and photosynthesis. Compared to untreated plants under heat stress, CTS-treated creeping bentgrass exhibited a significantly higher transcription level of genes involved in Chl biosynthesis (AsPBGD and AsCHLH), as well as a lower expression level of Chl degradation-related gene (AsPPH) and senescence-associated genes (AsSAG12, AsSAG39, Asl20, and Ash36), thus reducing leaf senescence and enhancing photosynthetic performance under heat stress. In addition, the foliar application of CTS significantly improved antioxidant enzyme activities (SOD, CAT, POD, and APX), thereby effectively reducing heat-induced oxidative damage. Furthermore, heat tolerance regulated by the CTS in creeping bentgrass was also associated with the heat shock pathway, since AsHSFA-6a and AsHSP82 were significantly up-regulated by the CTS during heat stress. The potential mechanisms of CTS-regulated thermotolerance associated with other metabolic pathways still need to be further studied in grass species.

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Characterization and Functional Analysis of FaHsfC1b from Festuca arundinacea Conferring Heat Tolerance in Arabidopsis

International Journal of Molecular Sciences ◽

10.3390/ijms19092702 ◽

2018 ◽

Vol 19 (9) ◽

pp. 2702 ◽

Cited By ~ 13

Author(s):

Lili Zhuang ◽

Wei Cao ◽

Jian Wang ◽

Jingjin Yu ◽

Zhimin Yang ◽

...

Keyword(s):

Heat Stress ◽

Transgenic Plants ◽

Heat Tolerance ◽

Festuca Arundinacea ◽

Photochemical Efficiency ◽

Grass Species ◽

Pcr Analysis ◽

Plant Tolerance ◽

Qrt Pcr ◽

Class C

Heat transcription factors (Hsfs) belong to a large gene family classified into A, B, and C groups, with classes A and B Hsfs being well-characterized and known for their roles in plant tolerance to abiotic stresses. The functions and roles of Class C Hsfs are not well-documented. The objectives of this study were to characterize a class C Hsf gene (FaHsfC1b) cloned from tall fescue (Festuca arundinacea), a perennial grass species, and to determine the physiological functions of FaHsfC1b in regulating heat tolerance by overexpressing FaHsfC1b in Arabidopsis thaliana. Full length cDNA of FaHsfC1b was cloned and the sequence alignment showed that it had high similarity to OsHsfC1b with typical DNA binding domain, hydrophobic oligomerization domain, and a nucleus localization signal. Transient expression with FaHsfC1b-eGFP in protoplasts of Arabidopsis leaves indicated its nucleus localization. qRT-PCR analysis showed that FaHsfC1b responded to heat, osmotic, salt, and cold stress in leaves and roots during 48-h treatment. Physiological analysis showed that FaHsfC1b overexpression enhanced plant survival rate, chlorophyll content, and photochemical efficiency, while it resulted in decreases in electrolyte leakage, H2O2 and O2− content under heat stress. qRT-PCR showed that endogenous HsfC1 was induced in transgenic plants and the expression levels of heat protection protein genes, including several HSPs, AtGalSyn1, AtRof1, and AtHSA32, as well as ABA-synthesizing gene (NCED3) were significantly upregulated in transgenic plants overexpressing FaHsfC1b under heat stress. Our results first demonstrate that HsfC1b plays positive roles in plant tolerance to heat stress in association with the induction and upregulation of heat-protective genes. HsfC1b may be used as a candidate gene for genetic modification of cool-season plant species for improving heat tolerance.

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Differential gene expression in shoots and roots under heat stress for a geothermal and non-thermal Agrostis grass species contrasting in heat tolerance

Environmental and Experimental Botany ◽

10.1016/j.envexpbot.2007.11.011 ◽

2008 ◽

Vol 63 (1-3) ◽

pp. 240-247 ◽

Cited By ~ 19

Author(s):

Jichen Xu ◽

Faith Belanger ◽

Bingru Huang

Keyword(s):

Gene Expression ◽

Heat Stress ◽

Differential Gene Expression ◽

Heat Tolerance ◽

Grass Species ◽

Differential Gene

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Differential Responses of Nutrients to Heat Stress in Warm-season and Cool-season Turfgrasses

HortScience ◽

10.21273/hortsci.44.7.2009 ◽

2009 ◽

Vol 44 (7) ◽

pp. 2009-2014 ◽

Cited By ~ 12

Author(s):

Hua Shen ◽

Hongmei Du ◽

Zhaolong Wang ◽

Bingru Huang

Keyword(s):

Heat Stress ◽

Heat Tolerance ◽

Poa Pratensis ◽

Warm Season ◽

Kentucky Bluegrass ◽

Grass Species ◽

Cool Season ◽

Temperature Conditions ◽

Differential Responses ◽

K Concentration

The objective of this study was to compare differential nutrient responses to heat stress in relation to heat tolerance for warm-season (C4) common bermudagrass [Cynodon dactylon (L.) Pers.] and cool-season (C3) kentucky bluegrass (Poa pratensis L.). Both species were exposed to two temperature regimes in growth chambers: optimal day/night temperature conditions (24/20 °C for kentucky bluegrass and 34/30 °C for bermudagrass) or heat stress (10 °C above the respective optimal temperature for each species). Heat injury in leaves was evaluated and the concentrations of several major macronutrients [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)] in both grass species were measured at 0, 7, 14, 21, and 28 days of treatment. Heat stress reduced leaf photochemical efficiency and cellular membrane stability in both species, but bermudagrass leaves exhibited less damage in these parameters than kentucky bluegrass. Heat stress caused a significant decline in N, P, and K concentration, beginning at 7 days in kentucky bluegrass, but had no significant effects on N, P, and K concentration in bermudagrass during the 28-day treatment period. The concentration of Ca and Mg increased under heat stress in both kentucky bluegrass and bermudagrass, but there were no significant differences between the species under optimal or high-temperature conditions, suggesting they were not involved in heat responses in either species. The differential responses of N, P, and K to heat stress could at least partially account for the differences in heat tolerance between the two species and demonstrate the importance of sufficient N, P, and K in turfgrass adaptation to heat stress.

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Exogenous Methyl Jasmonate Improves Heat Tolerance of Perennial Ryegrass Through Alteration of Osmotic Adjustment, Antioxidant Defense, and Expression of Jasmonic Acid-Responsive Genes

Frontiers in Plant Science ◽

10.3389/fpls.2021.664519 ◽

2021 ◽

Vol 12 ◽

Author(s):

Yanning Su ◽

Yizhi Huang ◽

Xintan Dong ◽

Ruijia Wang ◽

Mingyu Tang ◽

...

Keyword(s):

Heat Stress ◽

Jasmonic Acid ◽

Heat Tolerance ◽

Perennial Ryegrass ◽

Osmotic Adjustment ◽

Antioxidant Defense ◽

Grass Species ◽

Positive Role ◽

Heat Condition ◽

Study Results

Perennial ryegrass (Lolium perenne L.) is an important cool-season grass species that is widely cultivated in temperate regions worldwide but usually sensitive to heat stress. Jasmonates (JAs) may have a positive effect on plant tolerance under heat stress. In this study, results showed that exogenous methyl jasmonic acid (MeJA) could significantly improve heat tolerance of perennial ryegrass through alteration of osmotic adjustment, antioxidant defense, and the expression of JA-responsive genes. MeJA-induced heat tolerance was involved in the maintenance of better relative water content (RWC), the decline of chlorophyll (Chl) loss for photosynthetic maintenance, as well as maintained lower electrolyte leakage (EL) and malondialdehyde (MDA) content under heat condition, so as to avoid further damage to plants. Besides, results also indicated that exogenous MeJA treatment could increase the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), thus enhancing the scavenging ability of reactive oxygen species, alleviating the oxidative damage caused by heat stress. Heat stress and exogenous MeJA upregulated transcript levels of related genes (LpLOX2, LpAOC, LpOPR3, and LpJMT) in JA biosynthetic pathway, which also could enhance the accumulation of JA and MeJA content. Furthermore, some NAC transcription factors and heat shock proteins may play a positive role in enhancing resistance of perennial ryegrass with heat stress.

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Protein phosphorylation associated with drought priming-enhanced heat tolerance in a temperate grass species

Horticulture Research ◽

10.1038/s41438-020-00440-8 ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Xiaxiang Zhang ◽

Lili Zhuang ◽

Yu Liu ◽

Zhimin Yang ◽

Bingru Huang

Keyword(s):

Heat Stress ◽

Protein Phosphorylation ◽

Heat Tolerance ◽

Grass Species ◽

Phosphorylation Sites ◽

Biological Processes ◽

Plant Tolerance ◽

Motif Analysis ◽

Cross Tolerance ◽

Transcription Control

AbstractProtein phosphorylation is known to play crucial roles in plant tolerance to individual stresses, but how protein phosphorylation is associated with cross-stress tolerance, particularly drought priming-enhanced heat tolerance is largely unknown. The objectives of the present study were to identify phosphorylated proteins and phosphorylation sites that were responsive to drought priming and to determine whether drought priming-enhanced heat tolerance in temperate grass species involves changes in protein phosphorylation. Comparative analysis of phosphoproteomic profiles was performed on leaves of tall fescue (Festuca arundinacea) exposed to heat stress (38/33 °C, day/night) with or without drought priming. A total of 569 differentially regulated phosphoproteins (DRPs) with 1098 phosphorylation sites were identified in response to drought priming or heat stress individually or sequentially. Most DRPs were nuclear-localized and cytosolic proteins. Motif analysis detected [GS], [DSD], and [S..E] as major phosphorylation sites in casein kinase-II and mitogen-activated protein kinases regulated by drought priming and heat stress. Functional annotation and gene ontology analysis demonstrated that DRPs in response to drought priming and in drought-primed plants subsequently exposed to heat stress were mostly enriched in four major biological processes, including RNA splicing, transcription control, stress protection/defense, and stress perception/signaling. These results suggest the involvement of post-translational regulation of the aforementioned biological processes and signaling pathways in drought priming memory and cross-tolerance with heat stress in a temperate grass species.

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Antioxidant and Hormone Responses to Heat Stress in Two Kentucky Bluegrass Cultivars Contrasting in Heat Tolerance

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.139.5.587 ◽

2014 ◽

Vol 139 (5) ◽

pp. 587-596 ◽

Cited By ~ 9

Author(s):

Feifei Li ◽

Da Zhan ◽

Lixin Xu ◽

Liebao Han ◽

Xunzhong Zhang

Keyword(s):

Heat Stress ◽

Antioxidant Enzyme ◽

Heat Tolerance ◽

Poa Pratensis ◽

Perennial Grass ◽

Kentucky Bluegrass ◽

Grass Species ◽

Limiting Factor ◽

Antioxidant Enzyme Activities ◽

Aba Content

Heat stress is a major limiting factor for growth of cool-season perennial grass species, and mechanisms of heat tolerance have not been well understood. This study was designed to investigate antioxidant enzyme and hormone metabolism responses to heat stress in two kentucky bluegrass (Poa pratensis L.) cultivars contrasting in heat tolerance. The plants were subjected to 20/20 °C [day/night (control)] or 38/30 °C [day/night (heat stress)] for 28 days in growth chambers. Heat stress increased leaf electrolyte leakage (EL) and malondialdehyde (MDA) with heat-tolerant cultivar EverGlade exhibiting lower levels of EL and MDA relative to heat-sensitive cultivar Kenblue under heat stress. Superoxide dismutase (SOD) and catalase (CAT) activity increased and then declined during 28 days of heat stress. Peroxidase (POD) and ascorbate peroxidase (APX) activity declined and then increased during heat stress. ‘EverGlade’ had greater activities of SOD, CAT, POD, and APX relative to ‘Kenblue’ under heat stress. In addition, ‘EverGlade’ had two additional SOD isozymes and three additional POD isozymes relative to ‘Kenblue’ under heat stress. Leaf abscisic acid (ABA) increased in response to heat stress. Leaf indole-3-acetic acid (IAA) increased and then declined during heat stress. ‘OverGlade’ had higher ABA and IAA content relative to ‘Kenblue’. At the end of heat stress, leaf IAA and ABA content were 27.8% and 73% higher in ‘EverGlade’ relative to ‘Kenblue’, respectively. The results indicated that antioxidant enzymes and the hormones (ABA and IAA) were associated with kentucky bluegrass heat tolerance. Selection and use of cultivars with higher IAA and ABA content and greater antioxidant enzyme activities may improve kentucky bluegrass growth and quality under heat stress.

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Metabolic Responses to Heat Stress under Elevated Atmospheric CO2 Concentration in a Cool-season Grass Species

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.137.4.221 ◽

2012 ◽

Vol 137 (4) ◽

pp. 221-228 ◽

Cited By ~ 45

Author(s):

Jingjin Yu ◽

Hongmei Du ◽

Ming Xu ◽

Bingru Huang

Keyword(s):

Growth Rate ◽

Heat Stress ◽

Heat Tolerance ◽

Shoot Growth ◽

Shikimic Acid ◽

Membrane Stability ◽

Grass Species ◽

Glyceric Acid ◽

Cell Membrane Stability ◽

Shoot Growth Rate

Heat is a major factor limiting growth of C3 grass species. Elevated CO2 may mitigate the adverse effects of heat stress or enhance heat tolerance. The objective of this study was to determine metabolic changes associated with improvement of heat tolerance by elevated atmospheric CO2 concentration in tall fescue (Festuca arundinacea). Plants (cv. Rembrandt) were exposed to ambient day/night temperature (25/20 °C) or heat stress (35/30 °C) and ambient CO2 concentration (400 ± 10 μmol·mol−1) or double ambient CO2 concentration (800 ± 10 μmol·mol−1) in growth chambers. Turf quality (TQ), shoot growth rate, and leaf electrolyte leakage results demonstrated that heat stress at ambient CO2 concentration inhibits turf growth and reduces cell membrane stability, whereas heat-stressed plants under elevated CO2 concentration exhibit improved TQ, shoot growth rate, and membrane stability. Plants exposed to heat stress under elevated CO2 exhibited a significantly greater amount of several organic acids (shikimic acid, malonic acid, threonic acid, glyceric acid, galactaric acid, and citric acid), amino acids (serine, valine, and 5-oxoproline), and carbohydrates (sucrose and maltose) compared with heat-stressed plants at ambient CO2. The increased production or maintenance of metabolites with important biological functions such as those involved in photosynthesis, respiration, and protein metabolism could play a role in elevated CO2 mitigation of heat stress damage. Therefore, elevated CO2 conditions may contribute to improved heat stress tolerance as exhibited by better TQ and shoot growth of heat-stressed plants. Practices to harness the power of CO2 may be incorporated into turfgrass management for plant adaptation to increasing temperatures, particularly during summer months.

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Genotype-by-environment interaction in Holstein heifer fertility traits using single-step genomic reaction norm models

BMC Genomics ◽

10.1186/s12864-021-07496-3 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Rui Shi ◽

Luiz Fernando Brito ◽

Aoxing Liu ◽

Hanpeng Luo ◽

Ziwei Chen ◽

...

Keyword(s):

Heat Stress ◽

Dairy Cattle ◽

Candidate Genes ◽

Heat Tolerance ◽

Reaction Norm ◽

Single Step ◽

Conception Rate ◽

Critical Periods ◽

Genotype By Environment ◽

Fertility Traits

Abstract Background The effect of heat stress on livestock production is a worldwide issue. Animal performance is influenced by exposure to harsh environmental conditions potentially causing genotype-by-environment interactions (G × E), especially in highproducing animals. In this context, the main objectives of this study were to (1) detect the time periods in which heifer fertility traits are more sensitive to the exposure to high environmental temperature and/or humidity, (2) investigate G × E due to heat stress in heifer fertility traits, and, (3) identify genomic regions associated with heifer fertility and heat tolerance in Holstein cattle. Results Phenotypic records for three heifer fertility traits (i.e., age at first calving, interval from first to last service, and conception rate at the first service) were collected, from 2005 to 2018, for 56,998 Holstein heifers raised in 15 herds in the Beijing area (China). By integrating environmental data, including hourly air temperature and relative humidity, the critical periods in which the heifers are more sensitive to heat stress were located in more than 30 days before the first service for age at first calving and interval from first to last service, or 10 days before and less than 60 days after the first service for conception rate. Using reaction norm models, significant G × E was detected for all three traits regarding both environmental gradients, proportion of days exceeding heat threshold, and minimum temperature-humidity index. Through single-step genome-wide association studies, PLAG1, AMHR2, SP1, KRT8, KRT18, MLH1, and EOMES were suggested as candidate genes for heifer fertility. The genes HCRTR1, AGRP, PC, and GUCY1B1 are strong candidates for association with heat tolerance. Conclusions The critical periods in which the reproductive performance of heifers is more sensitive to heat stress are trait-dependent. Thus, detailed analysis should be conducted to determine this particular period for other fertility traits. The considerable magnitude of G × E and sire re-ranking indicates the necessity to consider G × E in dairy cattle breeding schemes. This will enable selection of more heat-tolerant animals with high reproductive efficiency under harsh climatic conditions. Lastly, the candidate genes identified to be linked with response to heat stress provide a better understanding of the underlying biological mechanisms of heat tolerance in dairy cattle.

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An ER–Golgi Tethering Factor SLOH4/MIP3 Is Involved in Long-term Heat Tolerance of Arabidopsis

Plant and Cell Physiology ◽

10.1093/pcp/pcaa157 ◽

2020 ◽

Author(s):

Kazuho Isono ◽

Ryo Tsukimoto ◽

Satoshi Iuchi ◽

Akihisa Shinozawa ◽

Izumi Yotsui ◽

...

Keyword(s):

Heat Stress ◽

Heat Tolerance ◽

Secretory Proteins ◽

Wild Type ◽

Additional Function ◽

Transcript Levels ◽

Unfolded Protein ◽

In The Wild ◽

Protein Response

Abstract Plants are often exposed not only to short-term (S-) heat stress but also to diurnal long-term (L-) heat stress over several consecutive days. To reveal the mechanisms underlying L-heat stress tolerance, we here used a forward genetic screening for sensitive to long-term heat (sloh) mutants and isolated sloh4. The mutant was hypersensitive to L- but not S-heat stress. The causal gene of sloh4 was identical to MIP3 encoding a member of the MAIGO2 (MAG2) tethering complex, which is composed of the MAG2, MIP1, MIP2, and MIP3 subunits and is localized at the endoplasmic reticulum (ER) membrane. Although sloh4/mip3 was hypersensitive to L-heat stress, the sensitivity of the mag2-3 and mip1–1 mutants was similar to that of the wild type. Under L-heat stress, the ER stress and the following unfolded protein response (UPR) were more pronounced in sloh4 than in the wild type. Transcript levels of bZIP60-regulated UPR genes were strongly increased in sloh4 under L-heat stress. Two processes known to be mediated by INOSITOL REQUIRING ENZYME1 (IRE1)—accumulation of the spliced bZIP60 transcript and a decrease in the transcript levels of PR4 and PRX34, encoding secretory proteins—were observed in sloh4 in response to L-heat stress. These findings suggest that misfolded proteins generated in sloh4 under L-heat stress may be recognized by IRE1 but not bZIP28, resulting in initiation of the UPR via activated bZIP60. Therefore, it would be possible that only MIP3 in MAG2 complex has an additional function in L-heat tolerance, which is not related to the ER–Golgi vesicle tethering.

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