# Tissue specific and abiotic stress regulated transcription of histidine kinases in plants is also influenced by diurnal rhythm

## TL;DR

This study explores how histidine kinase genes in plants respond to environmental stress, tissues, and daily cycles in Arabidopsis and rice.

## Contribution

The study reveals a complex regulatory network of TCS genes influenced by tissue, abiotic stress, and diurnal rhythm in plants.

## Key findings

- Rice expresses more TCS members under abiotic stress than Arabidopsis.
- TCS gene expression is regulated by tissue specificity and diurnal cycles in rice.
- TCS machinery shows tight regulation by multiple factors in both species.

## Abstract

Two-component system (TCS) is one of the key signal sensing machinery which enables species to sense environmental stimuli. It essentially comprises of three major components, sensory histidine kinase proteins (HKs), histidine phosphotransfer proteins (Hpts), and response regulator proteins (RRs). The members of the TCS family have already been identified in Arabidopsis and rice but the knowledge about their functional indulgence during various abiotic stress conditions remains meager. Current study is an attempt to carry out comprehensive analysis of the expression of TCS members in response to various abiotic stress conditions and in various plant tissues in Arabidopsis and rice using MPSS and publicly available microarray data. The analysis suggests that despite having almost similar number of genes, rice expresses higher number of TCS members during various abiotic stress conditions than Arabidopsis. We found that the TCS machinery is regulated by not only various abiotic stresses, but also by the tissue specificity. Analysis of expression of some representative members of TCS gene family showed their regulation by the diurnal cycle in rice seedlings, thus bringing-in another level of their transcriptional control. Thus, we report a highly complex and tight regulatory network of TCS members, as influenced by the tissue, abiotic stress signal, and diurnal rhythm. The insights on the comparative expression analysis presented in this study may provide crucial leads toward dissection of diverse role(s) of the various TCS family members in Arabidopsis and rice.