(Z)-3-Hexenol integrates drought and cold stress signaling by activating abscisic acid glucosylation in tea plants

Abstract

Cold and drought stresses severely limit crop production and can occur simultaneously. Although some transcription factors and hormones have been characterized in plants subjected each stress, the role of metabolites, especially volatiles, in response to cold and drought stress exposure is rarely studied due to lack of suitable models. Here, we established a model for studying the role of volatiles in tea (Camellia sinensis) plants experiencing cold and drought stresses simultaneously. Using this model, we showed that volatiles induced by cold stress promote drought tolerance in tea plants by mediating reactive oxygen species and stomatal conductance. Needle trap micro-extraction combined with GC-MS identified the volatiles involved in the crosstalk and showed that cold-induced (Z)-3-hexenol improved the drought tolerance of tea plants. In addition, silencing CsADH2 (Camellia sinensis alcohol dehydrogenase 2) led to reduced (Z)-3-hexenol production and significantly reduced drought tolerance in response to simultaneous cold and drought stress. Transcriptome and metabolite analyses, together with plant hormones comparison and abscisic acid (ABA) biosynthesis pathway inhibition experiments, further confirmed the roles of ABA in (Z)-3-hexenol-induced drought tolerance of tea plants. (Z)-3-hexenol application and gene silencing results supported the hypothesis that (Z)-3-hexenol plays a role in the integration of cold and drought tolerance by stimulating the dual function glucosyltransferase UGT85A53, thereby altering ABA homeostasis in tea plants. Overall, we present a model for studying the roles of metabolites in plants under multiple stresses and reveal the roles of volatiles in integrating cold and drought stresses in plants.

Comprehensive Analysis Reveals the Difference in Volatile Oil between Bupleurum marginatum var. stenophyllum (Wolff) Shan et Y. Li and the Other Four Medicinal Bupleurum Species

“…It has been shown that volatile compounds could ensure the survival of plants under severe cold conditions by maintaining membrane integrity and fluidity through the accelerated synthesis of abundant unsaturated fat [ 38 ]. Studies in several medicinal plants, such as Litsea cubeba , Camellia sinensis , and Astragalus mongholicus , have shown that the levels of their volatile oil are most positively correlated with higher latitude or lower annual average temperature [ 37 , 39 , 40 , 41 ]. The evolution research of the genus Juglans through pan-genome analyses further revealed that in eastern black walnut, with the sharp reduction of the effective population during the glacial climate, there was a large number of InDel sites in the genes involved in fatty acid synthesis [ 42 ].…”

Identification and Validation of the miR156 Family Involved in Drought Responses and Tolerance in Tea Plants (Camellia sinensis (L.) O. Kuntze)

“…To knock down csn-miR156f-2-5p expression, 1 mL of 50 μM AsODN-csn-miR156f-2-5p solution was injected into the leaves of hydroponic tea plant seedlings, and seedlings injected with sODN were used as controls. After incubation for 24 h, tea plants were treated with 15% ( w / v ) polyethyleneglycol (PEG) 6000 for 24 h (sODN/AsODN) [ 6 ]. Three independent biological replicates were established for each treatment.…”

“…These may be morphological, physiological, or related to water stress sensing, stress signal transduction, and related gene expression regulation [ 5 ]. Recent studies have shown that (Z)-3-hexanol and eugenol can enhance the drought tolerance of tea plants by mediating glucosylation [ 6 ]. An exogenous application of 24-epibrassinolide can improve the drought resistance of tea plants by promoting the expression of genes involved in the biosynthesis of galactinol and abscisic acid [ 7 ].…”

The Effect of Postharvest Storage Temperatures on Fruit Flavor Constituents in ‘Wushancuili’ Plum

“…By contrast, other higher-temperature storage may not efficiently prevent the release of ethylene and fruit respiration, which is not conducive to the maintenance of fruit quality. Aroma substances, such as 2-hexenal and (E)-3-hexen-1-ol [33,34], related to non-decay were more abundant at 0-2 • C, which was likely associated with the decrease in ethylene release and fruit energy metabolism during postharvest storage.…”