scholarly journals Cloning and Functional Analysis of Expansin TaEXPA9 Homologs in Winter Wheat in Frigid Regions

Author(s):  
Ziyi Zhao ◽  
Baozhong Hu ◽  
Xu Feng ◽  
Fenglan li ◽  
Fumeng He ◽  
...  

Abstract BackgroundLow temperature is an important factor that influences the ability of winter wheat to safely overwinter. Excessive low temperatures restrict the regrowth of winter wheat, thus decreasing agricultural output. Non-enzymatic expansins, which are related to plant growth, have been reported to respond to drought, salinity, and low temperature stress. We obtained an expansin gene, TaEXPA9, that is induced by low temperature from a transcriptome analysis of ‘Dongnong winter wheat no. 2’—a winter wheat with high cold hardiness—but the expression pattern and function of this gene were unknown. We therefore analyzed the expression patterns of TaEXPA9-A/B/D in D2 in response to different abiotic stresses and exogenous phytohormone treatments in different organs. The entire length of TaEXPA9-A/B/D was obtained, and green fluorescent labeling was used for subcellular localization analysis of TaEXPA9-A/B/D on onion epidermis. The 35S::TaEXPA9-A/B/D expression vector was constructed, and an overexpression transgenic Arabidopsis thaliana line was obtained to examine the effects of the homologs of this expansin on plant growth and low temperature stress resistance. ResultsThe results showed that TaEXPA9-A/B/D transcription significantly increased at 4°C low temperature stress, its expression level was higher in the roots, and TaEXPA9-A/B/D was localized to the cell wall. The roots were well-developed in the overexpression A. thaliana, and the growth-related markers and setting rate were better than in the wild-type. Recovery was stronger in the overexpression plants after frost stress. At 4°C low temperature stress, the antioxidant enzyme activity and osmoregulatory substance content in the TaEXPA9-A/B/D-overexpressing A. thaliana plants were significantly higher than in the wild-type plants, and the degree of membrane lipid peroxidation was lower. ConclusionsIn summary, TaEXPA9-A/B/D participates in the low-temperature stress response and may increase the scavenging of reactive oxygen species caused by low temperature stress through the protective enzyme system. Additionally, TaEXPA9-A/B/D can increase the levels of small molecular organic substances to resist osmotic stress caused by low temperature.

2021 ◽  
Vol 12 ◽  
Author(s):  
Jie Dong ◽  
Lei Cao ◽  
Xiaoying Zhang ◽  
Wuhua Zhang ◽  
Tao Yang ◽  
...  

A sudden cooling in the early spring or late autumn negatively impacts the plant growth and development. Although a number of studies have characterized the role of the transcription factors (TFs) of plant R2R3-myeloblastosis (R2R3-MYB) in response to biotic and abiotic stress, plant growth, and primary and specific metabolisms, much less is known about their role in Rosa multiflora under chilling stress. In the present study, RmMYB108, which encodes a nuclear-localized R2R3-MYB TF with a self-activation activity, was identified based on the earlier published RNA-seq data of R. multiflora plants exposed to short-term low-temperature stress and also on the results of prediction of the gene function referring Arabidopsis. The RmMYB108 gene was induced by stress due to chilling, salt, and drought and was expressed in higher levels in the roots than in the leaves. The heterologous expression of RmMYB108 in Arabidopsis thaliana significantly enhanced the tolerance of transgenic plants to freezing, water deficit, and high salinity, enabling higher survival and growth rates, earlier flowering and silique formation, and better seed quantity and quality compared with the wild-type (WT) plants. When exposed to a continuous low-temperature stress at 4°C, transgenic Arabidopsis lines–overexpressing RmMYB108 showed higher activities of superoxide dismutase and peroxidase, lower relative conductivity, and lower malondialdehyde content than the WT. Moreover, the initial fluorescence (Fo) and maximum photosynthetic efficiency of photosystem II (Fv/Fm) changed more dramatically in the WT than in transgenic plants. Furthermore, the expression levels of cold-related genes involved in the ICE1 (Inducer of CBF expression 1)-CBFs (C-repeat binding factors)-CORs (Cold regulated genes) cascade were higher in the overexpression lines than in the WT. These results suggest that RmMYB108 was positively involved in the tolerance responses when R. multiflora was exposed to challenges against cold, freeze, salt, or drought and improved the cold tolerance of transgenic Arabidopsis by reducing plant damage and promoting plant growth.


1988 ◽  
Vol 66 (8) ◽  
pp. 1610-1615 ◽  
Author(s):  
D. A. Gaudet ◽  
T. H. H. Chen

The relationship between snow mold resistance and freezing resistance was studied under controlled-environment conditions, using winter wheat (Triticum aestivum L. em. Thell) cultivars varying in freezing resistance and resistance to cottony snow mold (Coprinus psychromorbidus Redhead & Traquair). Cultivars varying in freezing resistance were equally susceptible to C. psychromorbidus. There existed a negative relationship between snow mold resistance and freezing resistance. Sublethal, subzero freezing temperatures between −3 and −12 °C predisposed the winter wheat cultivar 'Winalta' to increased damage by C. psychromorbidus. A synergistic effect resulting in increased mortality was observed when winter wheat plants received a combination of low-temperature stress and inoculation with C. psychromorbidus. In hardened winter wheat plants, sublethal levels of snow mold damage following 6 weeks incubation with C. psychromorbidus resulted in a reduction in freezing resistance or LT50 (50% killing temperature) of approximately 7 °C compared with the noninoculated controls. The possible role of low-temperature stress on the susceptibility of winter wheats to C. psychromorbidus and of snow mold infection on the retention of freezing resistance in winter wheats during winter in the central and northern Canadian prairies is discussed.


2019 ◽  
Author(s):  
Xiaolong Wang ◽  
Huiqing Jin ◽  
Kai Meng ◽  
Zhenyu Jia ◽  
Shiyuan Yan ◽  
...  

Abstract Abstract Background: Alfalfa ( Medicago sativa ) is a perennial forage crop widely cultivated in northern China. The root crown of alfalfa is an important storage organ in the process of wintering, and it is closely related to the winter hardiness of alfalfa. At present, the specific molecular mechanism of response to winter hardiness in alfalfa root crown is unclear. The transcriptome database created by RNA sequencing (RNA-seq) is widely used to identify the critical genes related to winter hardiness. Results: The transcriptomes of alfalfa varieties, such as “Lomgmu 806” (with high winter survival rate) and “Sardi” (with low winter survival rate) have been sequenced in the study. Among the identified 57,712 unigenes, 2,299 differentially expressed genes (DEGs) were up-regulated, and 2,143 unigenes were down-regulated in the Lomgmu 806 vs Sardi root crown. The KEGG pathway annotations showed that 1,159 unigenes were mainly annotated to 116 pathways. Seven DEGs belonging to “plant hormone signaling transduction”, “peroxidase” pathway and transcription factors family (MYB, B3, AP2/ERF, WRKY) genes involved in alfalfa winter hardiness. Among them, the expression patterns of seven DEGs were verified by real-time quantitative PCR (RT-qPCR) analyses, which verified the reliable results of transcriptome sequencing analyses. Conclusions: RNA-Seq was used to discover genes associated with the wintering differences between alfalfa varieties. The transcriptome data showed that the gene regulation response of alfalfa to low temperature stress, which provides a valuable resource for further identification and functional analysis of candidate genes for winter hardiness of alfalfa. In addition, these data provide references for future study of genetic breeding and winter hardiness in alfalfa.


2020 ◽  
Vol 107 (4) ◽  
pp. 329-336
Author(s):  
Andrius Aleliūnas ◽  
Kristina Jaškūnė ◽  
Gražina Statkevičiūtė ◽  
Gabija Vaitkevičiūtė ◽  
Gintaras Brazauskas ◽  
...  

2018 ◽  
Vol 19 (9) ◽  
pp. 2579 ◽  
Author(s):  
Aimin Zhou ◽  
Enhui Liu ◽  
He Li ◽  
Yang Li ◽  
Shuang Feng ◽  
...  

Low temperature stress adversely affects plant growth and development. Isolation and characterization of cold response genes from cold-tolerant plants help to understand the mechanism underlying low temperature tolerance. In this study, PsCor413pm2, a cold-regulated (COR) gene isolated from Phlox subulata, was transferred to Arabidopsis plants to investigate its function. Real-time quantitative PCR analysis revealed that PsCor413pm2 expression was induced by cold. Subcellular localization revealed that the PsCor413pm2-green fluorescent protein (GFP) fusion protein localized to the plasma membrane in tobacco and Arabidopsis plants. Furthermore, overexpression of PsCor413pm2 in Arabidopsis plants enhanced tolerance to low temperature stress. Transgenic Arabidopsis roots had more influx of Ca2+ after a cold shock than wild-type plants, as shown using non-invasive micro-test technology (NMT). Moreover, the transcription abundance of five COR and two C-repeat (CRT) binding factor (CBF) genes in transgenic Arabidopsis plants was higher than that in the wild-type plants under cold stress. Taken together, our results suggest that overexpression of PsCor413pm2 enhances low temperature tolerance in Arabidopsis plants by affecting Ca2+ flux and the expression of stress-related COR and CBF genes.


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