  Plant electrical signals have been shown to be generated in response to
various environmental stresses, but the relationship between these signals and
stress tolerance is not well understood. In this study, we used the Arabidopsis
STTM165/166 mutant, which exhibits enhanced temperature tolerance, to examine
this relationship. Surface recording techniques were utilized to compare the
generation ratio and duration characteristics of electrical signals in the
STTM165/166 mutant and wild type (WT). Patch-clamp recording was employed to
assess ion channel currents, specifically those of calcium ions. The current
intensity of the mutant was found to be lower than that of the WT. As calcium
ions are involved in the generation of plant electrical signals, we
hypothesized that the reduced calcium channel activity in the mutant increased
its electrical signal threshold. RNA-Seq analysis revealed differential
expression of AHA genes in the STTM165/166 mutant, which may contribute to the
prolonged depolarization phenotype. Gene Ontology enrichment of differentially
expressed genes (DEGs) identified associations between these DEGs and various
stresses, including temperature, salt, and those related to the jasmonic acid
and abscisic acid pathways. These findings provide experimental evidence for
the use of plant electrical signals in characterizing stress tolerance and
explore potential ion mechanisms through patch-clamp recording and DEG Gene
Ontology analysis. They also emphasize the need for further research on the
relationship between plant electrical signals and stress tolerance.
