Unique miRNAs and their targets in tomato leaf responding to combined drought and heat stress

Abstract

Background: Both drought and heat stress are serious global problems, leading to agricultural production loss. MicroRNAs (miRNAs) play important roles in plant species responding to individual drought and heat stress. However, the miRNAs and mRNAs in association with combined drought and heat in crops like tomato remains unclear. Results:We studied the crosstalk of miRNAs and their target genes in tomato plants grown under simultaneous drought and heat stress that frequently happen in field conditions. In total, 335 known miRNAs representing 55 miRNA families and 430 potential novel miRNAs were identified in Solanum lycopersicum L. using small RNA deep sequencing. Through expression analysis, miRNAs in association with drought, heat and the combination of these were investigated. In total, 61, 74 and 37 miRNAs were differentially regulated for combination (of both stresses) vs control, combination vs drought and combination vs heat, respectively. Target genes with different expression levels were found using degradome sequencing, which were mainly involved in transcription factor activity, sequencespecific DNA binding, transcription, regulation of transcription, nucleus, DNA binding etc. The quantitative real-time polymerase chain reaction (qRT-PCR) results confirmed the accuracy of sequencing.Conclusions: Our study serves as valuable knowledge on how crop adapted to combined drought and heat stress by regulating miRNAs and mRNAs, which provide information for crop improvement to deal with future climate changes.

Combined Stress Conditions in Melon Induce Non-additive Effects in the Core miRNA Regulatory Network

“…On the other hand, non-additive miRNAs might be part of a more specific regulatory response to each particular stress condition. This viewing is consistent with an anticipated notion that plants may use the miRNA-mediated regulation as a pivotal mechanism to mediate the response to both simple and combined stresses ( Zhang, 2015 ; Samad et al, 2017 ; Zhu et al, 2019 ; Zhou et al, 2020 ).…”

“…Although increasing pieces of evidence support the role of miRNAs as key modulators of plant response to both biotic ( Sun et al, 2017 ; Xie et al, 2017 ; Brant and Budak, 2018 ) and abiotic stress conditions ( Cervera-Seco et al, 2019 ; Wang et al, 2020 ; Cheng et al, 2021 ; Zhao et al, 2021 ), research focusing on elucidating the regulatory role of the miRNAs during exposure to combined adverse environmental conditions is still scarce ( Xu et al, 2019 ), and only a few studies considering the effects of a unique combination of stresses have been addressed in soybean ( Ning et al, 2019 ), A. thaliana ( Gupta et al, 2020 ), wheat ( Liu et al, 2020 ), and tomato ( Zhou et al, 2020 ).…”

MicroRNAs: Potential Targets for Developing Stress-Tolerant Crops

“…Nitrogen starvation [149] miR156, miR164, miR167, miR168, miR528, miR820, miR821, miR1318 Low-nitrogen stress [150] multiple miRNAs Abiotic stress [151] osa-miR414, osa-miR164e, osa-miR408 Salt stress [152] Soybean (Glycine max) multiple miRNAs Water deficit [153] Sugarcane (Saccharum L.) multiple miRNAs Water-deficit stress [154] multiple miRNAs Low temperature stress [155] multiple miRNAs Waterlogging condition [156] multiple miRNAs Drought stress [157] multiple miRNAs Drought stress [158] Sweet Potato (Ipomoea batatas) multiple miRNAs Drought and CO 2 stress [159] multiple miRNAs Salt stress [160] Switchgrass (Panicum virgatum) multiple miRNAs Drought and heat stress [161] multiple miRNAs Salt stress [162] Tobacco (Nicotiana tabacum) multiple miRNAs Salt and alkali stress [163] Tomato (Solanum lycopersicum) multiple miRNAs Drought and heat stress [164] multiple miRNAs Drought stress [165] Turnip (Brassica rapa) miR166h-3p-1, miR398b-3p, miR398b-3p-1, miR408d, miR156a-5p, miR396h, miR845a-1, miR166u, Bra-novel-miR3153-5p and Bra-novel-miR3172-5p…”

Down-Regulation of Cytokinin Receptor Gene SlHK2 Improves Plant Tolerance to Drought, Heat, and Combined Stresses in Tomato

“…Various abiotic stresses naturally coincide in the field, where plants are exposed to multiple abiotic stresses. Among these stresses, heat and drought are significant constraints on global plant growth and food security [5,6].…”