Functional characterization and regulatory mechanism of wheat CPK34 kinase in response to drought stress

Abstract

Background: Drought is one of the most adverse environmental factors limiting crop productions and it is important to identify key genetic determinants for food safety. Calcium-dependent protein kinases (CPKs) are known to be involved in plant growth, development, and environmental stresses. However, biological functions and regulatory mechanisms of many plant CPKs have not been explored. In our previous study, abundance of the wheat CPK34 (TaCPK34) protein was remarkably upregulated in wheat plants suffering from drought stress, inferring that it could be involved in this stress. Therefore, here we further detected its function and mechanism in response to drought stress. Results: Transcripts of the TaCPK34 gene were significantly induced after PEG-stimulated water deficiency (20% PEG6000) or 100 μM abscisic acid (ABA) treatments. The TaCPK34 gene was transiently silenced in wheat genome by using barley stripe mosaic virus-induced silencing (BSMV-VIGS) method. After 14 days of drought stress, the transiently TaCPK34-silenced wheat seedlings showed more sensitivity compared with control, and the plant biomasses and relative water contents significantly decreased, whereas soluble sugar and MDA contents increased. The iTRAQ-based quantitative proteomics was employed to measure the protein expression profiles in leaves of the transiently TaCPK34-silenced wheat plants after drought stress. There were 6103 proteins identified, of these, 51 proteins exhibited significantly altered abundance, they were involved in diverse function. And sequence analysis on the promoters of genes, which encoded the above identified proteins, indicated that some promoters harbored some ABA-responsive elements. We determined the interactions between TaCPK34 and three identified proteins by using bimolecular fluorescent complementation (BiFC) method and our data indicated that TaCPK34directly interacted with the glutathione S-transferase 1 and prx113, respectively. Conclusions: Our study suggested that the TaCPK34 gene played positive roles in wheat response to drought stress through directly or indirectly regulating the expression of ABA-dependent manner genes, which were encoding identified proteins from iTRAQ-based quantitative proteomics. And it could be used as one potential gene to develop crop cultivars with improved drought tolerance.

An Efficient Brome mosaic virus-Based Gene Silencing Protocol for Hexaploid Wheat (Triticum aestivum L.)

“…Among those developed for monocotyledons, three have been applied to silence genes in wheat. Barley stripe mosaic virus (BSMV) has been extensively employed to assess gene function in wheat, as well as other Triticeae species (Dommes et al, 2019;Li et al, 2020;Zhou et al, 2020). The recently developed Foxtail mosaic virus (FoMV)-based VIGS system triggered efficient gene silencing in a broad range of host plants, including wheat (Liu et al, 2016;Mei et al, 2016).…”

iTRAQ based protein profile analysis revealed key proteins involved in regulation of drought-tolerance during seed germination in Adzuki bean

“…PVX based vector can be used to mediate high expression of foreign genes, and the overexpressed protein can move away from the initially infected cells to the uninfected sites 19 , 20 . Virus-based vectors were used to investigate gene function involved in drought stress 21 , 22 . In this study, V-ATPase (A0A0L9TJ92) was up-regulated in 17235T compared to 17033T, and its expression levels at transcriptomic and proteomic level were consistent.…”

The Calcium-Dependent Protein Kinase TaCDPK27 Positively Regulates Salt Tolerance in Wheat

“…Growing evidence has confirmed the important roles of plant CDPKs in stress signal transduction [16]. Barley HvCPK2a and wheat TaCDPK34 are CDPKs proved to be involved in the plant response to drought stress with opposite roles [18,19]. Overexpression of HvCPK2a led to increased drought sensitivity in barley [18], while it is silencing of TaCDPK34 that leads to a similar phenotype in wheat [19].…”

“…Barley HvCPK2a and wheat TaCDPK34 are CDPKs proved to be involved in the plant response to drought stress with opposite roles [18,19]. Overexpression of HvCPK2a led to increased drought sensitivity in barley [18], while it is silencing of TaCDPK34 that leads to a similar phenotype in wheat [19]. Rice OsCDPK21 and OsCDPK10, Glycyrrhiza uralensis GuCDPKs, maize ZmCDPK11, and apple MdCDPK1a are CDPKs improved by plant responses to salt stress [17,[20][21][22][23].…”