WRKY41/WRKY46-miR396b-5p-TPR module mediates abscisic acid-induced cold tolerance of grafted cucumber seedlings

Abstract

Grafting is one of the key agronomic measures to enhance the tolerance to environmental stresses in horticultural plants, but the specific molecular regulation mechanism in this tolerance largely remains unclear. Here, we found that cucumber grafted onto figleaf gourd rootstock increased cold tolerance through abscisic acid (ABA) activating WRKY41/WRKY46-miR396b-5p-TPR (tetratricopeptide repeat-like superfamily protein) module. Cucumber seedlings grafted onto figleaf gourd increased cold tolerance and induced the expression of miR396b-5p. Furthermore, overexpression of cucumber miR396b-5p in Arabidopsis improved cold tolerance. 5’ RNA ligase-mediated rapid amplification of cDNA ends (5’ RLM-RACE) and transient transformation experiments demonstrated that TPR was the target gene of miR396b-5p, while TPR overexpression plants were hypersensitive to cold stress. The yeast one-hybrid and dual-luciferase assays showed that both WRKY41 and WRKY46 bound to MIR396b-5p promoter to induce its expression. Furthermore, cold stress enhanced the content of ABA in the roots and leaves of figleaf gourd grafted cucumber seedlings. Exogenous application of ABA induced the expression of WRKY41 and WRKY46, and cold tolerance of grafted cucumber seedlings. However, figleaf gourd rootstock-induced cold tolerance was compromised when plants were pretreated with ABA biosynthesis inhibitor. Thus, ABA mediated figleaf gourd grafting-induced cold tolerance of cucumber seedlings through activating the WRKY41/WRKY46-miR396b-5p-TPR module.

GWAS reveals novel loci and identifies a pentatricopeptide repeat-containing protein (CsPPR) that improves low temperature germination in cucumber

“…The regulatory mechanisms of LT response are complex and dynamic processes ( Ding et al., 2019 ; Ding and Yang, 2022 ; Kidokoro et al., 2022 ), involving the perception of signals at the cytomembrane, transduction of the signal from the cytomembrane to the cell nucleus, and the activation of regulatory mechanisms in the cell nucleus. Correspondingly, multiple factors participate in the LT regulatory response, including, transcription factors PPR ( Xing et al., 2018 ), NAC ( Zhuo et al., 2018 ; Liu et al., 2020a ), GRAS ( Wang et al., 2021 ; Li et al., 2022a ), bZIP ( Li et al., 2022b ) and WRKY ( Liu et al., 2022b ; Sun et al., 2022a ; Zhang et al., 2022 ; Zhao et al., 2022 ), phytohormones ABA ( Zhu, 2016 ; Song et al., 2022 ; Zhang et al., 2023 ), JA ( Li et al., 2021 ; Sun et al., 2022b ) and GA ( Magome et al., 2004 ; Achard et al., 2008 ) and various metabolic pathways especially those producing compatible solutes. In this study, ten genes in the GWAS regions, possibly related to abiotic stress were identified ( Table S8 ).…”

Advances in understanding cold tolerance in grapevine

“…Grafting is an important agronomic technology to improve the quality traits and/or tolerance of scions to environmental stresses. Enhanced cold tolerance of grafted seedlings has been accomplished recently in watermelon ( Citrullus lanatus ) and cucumber ( Cucumis sativus ), respectively ( Lu et al 2022 ; Sun et al 2022 ). Actually, grafting with grapevine rootstocks could promote expression of numerous TFs and accumulation of stilbene, flavonol, and ABA in scions ( Chitarra et al 2017 ; Zhang et al 2022a ).…”

CsWRKY11 cooperates with CsNPR1 to regulate SA-triggered leaf de-greening and reactive oxygen species burst in cucumber

“…In cucumber, WRKYs were reported participating in regulating its resistance to biotic and abiotic stresses (Chen et al 2020 ; Yang et al 2020 ; Meng et al 2022 ). ABA mediates the cold response of cucumber via regulating the CsWRKY41/CsWRKY46-miR396b-5p-CsTPR module (Sun et al 2022 ). CsWRKY50 positively regulates the immune response of cucumber plants to Pseudoperonospora cubensis through enhancing their antioxidation activity (Luan et al 2019 ).…”