Heat Stress Resistance Mechanisms of Two Cucumber Varieties from Different Regions

Abstract

High temperatures affect the yield and quality of vegetable crops. Unlike thermosensitive plants, thermotolerant plants have excellent systems for withstanding heat stress. This study evaluated various heat resistance indexes of the thermotolerant cucumber (TT) and thermosensitive cucumber (TS) plants at the seedling stage. The similarities and differences between the regulatory genes were assessed through transcriptome analysis to understand the mechanisms for heat stress resistance in cucumber. The TT plants exhibited enhanced leaf status, photosystem, root viability, and ROS scavenging under high temperature compared to the TS plants. Additionally, transcriptome analysis showed that the genes involved in photosynthesis, the chlorophyll metabolism, and defense responses were upregulated in TT plants but downregulated in TS plants. Zeatin riboside (ZR), brassinosteroid (BR), and jasmonic acid (JA) levels were higher in TT plants than in TS. The heat stress increased gibberellic acid (GA) and indoleacetic acid (IAA) levels in both plant lines; however, the level of GA was higher in TT. Correlation and interaction analyses revealed that heat cucumber heat resistance is regulated by a few transcription factor family genes and metabolic pathways. Our study revealed different phenotypic and physiological mechanisms of the heat response by the thermotolerant and thermosensitive cucumber plants. The plants were also shown to exhibit different expression profiles and metabolic pathways. The heat resistant pathways and genes of two cucumber varieties were also identified. These results enhance our understanding of the molecular mechanisms of cucumber response to high-temperature stress.

Intrinsically disordered protein, DNA binding with one finger transcription factor (OsDOF27) implicates thermotolerance in yeast and rice

“…JrGRAS2 in turn regulates the expression of heat shock proteins and thereby improves high temperature stress tolerance (Yang et al, 2018). In a recent transcriptomics study in cucumber, DOF transcription factor was found to be upregulated (Yu et al, 2022). A transcriptomic and proteomic analysis would be conducted to understand the candidate molecular targets of OsDOF27, which will allow us to get deeper insight and delineate the detailed molecular mechanisms of heat stress tolerance imparted by DOF27 in rice.…”

Physiological Study of the Efficacy of Archer® Eclipse in the Protection against Sunburn in Cucumber Plants

“…The daily stress period could have drastically decreased the A CO2 and gs, as cucumber plants are a thermophilic crop that grows optimally at 25 • C [30], but temperatures above 35-50 • C can lead to leaf damage and even dead tissue [31]. Under these conditions, it has been reported that both thermo-tolerant and thermo-sensitive cucumber species show decreased leaf gas exchange parameters, but only thermo-tolerant cucumber species restore functions to a relatively healthy level after high-temperature exposure [32]. Nevertheless, A CO2 and g s reduction in treated plants could be due to an adaption mechanism to high light and temperature favoured by Archer ® Eclipse's application, since leaf damage was not observed and Fv/Fm, PIABS, RC/ABS, and ΨEO values were higher than in non-treated plants [15].…”

The Physiology of Postharvest Tea (Camellia sinensis) Leaves, According to Metabolic Phenotypes and Gene Expression Analysis

“…The maximum photochemical efficiency of PSII (Fv/Fm) was measured with an IMAGING-PAM chlorophyll fluorescence system (Heinz Walz GmbH, Effeltrich, Germany) using default parameters according to Yu’s [ 25 ]. After tea leaves adapted to the dark for 20 min, Fo was measured.…”