Search

Background: Abscisic acid (ABA) is an important stress hormone, the changes of abscisic acid content can alter plant tolerance to stress, abscisic acid is crucial for studying plant responses to abiotic stress. The abscisic acid aldehyde oxidase (AAO) plays a vital role in the final step in the synthesis of abscisic acid, therefore, understanding the function of AAO gene family is of great significance for plants to response to abiotic stresses. Result: In this study, 6, 8, 4 and 4 AAO genes were identified in four cotton species. According to the structural characteristics of genes and the traits of phylogenetic tree, we divided the AAO gene family into 4 clades. Gene structure analysis showed that the AAO gene family was relatively conservative. The analysis of cis-elements showed that most AAO genes contained cis-elements related to light response and plant hormones. Tissue specificity analysis under NaHCO3 stress showed that GhAAO2 gene was differentially expressed in both roots and leaves. After GhAAO2 gene silencing, the degree of wilting of seedlings was lighter than that of the control group, indicating that GhAAO2 could respond to NaHCO3 stress. Conclusions: In this study, the AAO gene family was analyzed by bioinformatics, the response of GhAAO gene to various abiotic stresses was preliminarily verified, and the function of the specifically expressed gene GhAAO2 was further verified. These findings provide valuable information for the study of potential candidate genes related to plant growth and stress. [ABSTRACT FROM AUTHOR]

Glutamate decarboxylase (GAD) mainly regulated the biosynthesis of γ-aminobutyric acid (GABA) and played an important role in plant growth and stress resistance. To explore the potential function of GAD in cotton growth, the genome-wide identification, structure, and expression analysis of GAD genes were performed in this study. There were 10, 9, 5, and 5 GAD genes identified in G. hirsutum , G. barbadense , G. arboreum , and G. raimondii , respectively. GAD was divided into four clades according to the protein motif composition, gene structure, and phylogenetic relationship. The segmental duplication was the main way of the GAD gene family evolution. Most GhGADs respond to abiotic stress. Clade Ⅲ GAD was induced by Cd 2+ stress, especially GhGAD6 , and silencing GhGAD6 would lead to more serious Cd 2+ poisoning in cotton. The oxidative damage caused by Cd 2+ stress was relieved by increasing the GABA content. It was speculated that the decreased expression of GhGAD6 reduced the content of GABA in vivo and caused the accumulation of ROS. This study will further expand our understanding of the relationship between the evolution and function of the GhGAD gene family and provide new genetic resources for cotton breeding under environmental stress and phytoremediation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Huang, He, Cui, Sun, Han, Wang, Rui, Lei, Liu, Xu, Zhang, Zhang, Fan, Feng, Ni, Jiang, Zhang, Chen, Wang, Chen, Lu, Wang, Wang, Yin, Qaraevna, Guo, Zhao and Ye.)

Ca 2+ is an essential nutrient for plants and animals which plays an important role in plant signal transduction. Although the function and regulation of mechanism of Ca 2+ in alleviating various biotic and abiotic stresses in plants have been studied deeply, the molecular mechanism to adapt high Ca 2+ stress is still unclear in cotton. In this study, 103 cotton accessions were germinated under 200 mM CaCl 2 stress, and two extremely Ca 2+ -resistant (Zhong 9807, R) and Ca 2+ -sensitive (CRI 50, S) genotypes were selected from 103 cotton accessions. The two accessions were then germinated for 5 days in 0 mM CaCl 2 and 200 mM CaCl 2 respectively, after which they were sampled for transcriptome sequencing. Morphological and physiological analyses suggested that PLR2 specifically expressed in R may enhance the ability of cotton to scavenge ROS by promoting the synthesis of SDG. In conclusion, this study proposed the adaptation mechanisms to response to the high Ca 2+ stress in cotton which can contribute to improve the stress resistance of cotton., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)