Knockout of SlMAPK3 enhances tolerance to heat stress involving ROS homeostasis in tomato plants

Abstract

Background High temperature is a major environmental stress that limits plant growth and agriculture productivity. Mitogen-activated protein kinases (MAPKs) are highly conserved serine and threonine protein kinases that participate in response to diverse environmental stresses in plants. A total of 16 putative SlMAPK genes are identified in tomato, and SlMAPK3 is one of the most extensively studied SlMAPKs . However, the role of SlMAPK3 in response to heat stress is not clearly understood in tomato plants. In this study, we performed functional analysis of SlMAPK3 for its possible role in response to heat stress. Results qRT-PCR analyses revealed that SlMAPK3 relative expression was depressed by heat stress. Here, wild-type (WT) tomato plants and CRISPR/Cas9-mediated slmapk3 mutant lines (L8 and L13) were used to investigate the function of SlMAPK3 in response to heat stress. Compared with WT plants, slmapk3 mutants exhibited less severe wilting and less membrane damage, showed lower reactive oxygen species (ROS) contents, and presented higher both activities and transcript levels of antioxidant enzymes, as well as elevated expressions of genes encoding heat stress transcription factors ( HSFs ) and heat shock proteins ( HSPs ). Conclusions CRISPR/Cas9-mediated slmapk3 mutants exhibited more tolerance to heat stress than WT plants, suggesting that SlMAPK3 was a negative regulator of thermotolerance. Moreover, antioxidant enzymes and HSPs / HSFs genes expression were involved in SlMAPK3 -mediated heat stress response in tomato plants. Electronic supplementary material The online version of this article (10.1186/s12870-019-1939-z) contains supplementary material, which is available to authorized users.

Dissecting the Molecular Function of Triticum aestivum STI Family Members Under Heat Stress

“…It was observed that the relative expression of AtHSFA2 , AtHSFA6 , and AtHSFA7 was found to be higher in overexpression lines than the WT under both control as well as after HS conditions ( Figure 12 ). Apart from these, the expression of antioxidant enzymes were checked as ROS detoxification aids in HS adaptation and in possession of thermotolerance ( Yu et al, 2019 ). The expression of AtAPX2 was found to be upregulated in overexpression lines under HS conditions in comparison to the WT ( Figure 12 ).…”

Recapitulation of the Function and Role of ROS Generated in Response to Heat Stress in Plants

“…The most significant example given in a study was done on mitogen-activated protein kinase (MAPK) cascades. MAPK cascades are a part of signal transduction involved in plant development, hormone regulation, disease resistance, and stress responses [ 77 ]. Specifically, tomato MAK3 (SIMAPK3) has been known to defend against abiotic and biotic stresses.…”

Can omics deliver temperature resilient ready-to-grow crops?

“…In short, ONAC127 and ONAC129, along with multiple pathways (sugar transportation), regulate caryopsis filling, including monosaccharide transporter OsMST6, sugar transporter OsSWEET4, calmodulin-like protein OsMSR2, AP2/ERF, OsEATB, cell wall construction, and nutrient transport under HS [66]. In tomato, CRISPRmediated Simapk3 mutant unveiled improved tolerance to HS, less cell damage and wilting, lower ROS contents, increasing antioxidant activity, and the higher expression of genes encoding heat shock factors/proteins (HSFs and HSPs) that mainly regulates HS [133]. In a different study, brassinazole resistant (BZR1) like protein available in tomato is involved in HS tolerance.…”