The more you know: A role for circadian clock activators in stress responses

MARÍA JOSÉ DE LEONE; ABRIL SAN MARTÍN; CLARA GAGUINE; ESTEBAN HERNANDO

Santa Fe

Congreso; RAFV 2021; 2021

SAFV

Light signaling pathways interact with the circadian clock to help organisms synchronize physiological and developmental processes to periodical environmental changes. The plant photoreceptors responsible for clock resetting have been characterized, but signaling components that link the photoreceptors to the clock remain to be identified. Members of the family of NIGHT LIGHT?INDUCIBLE AND CLOCK-REGULATED (LNK) and REVEILLE (RVE) genes play key roles linking light regulation of gene expression to the control of daily and seasonal rhythms in Arabidopsis thaliana. Particularly, plants defective in LNK (lnk1;2 and lnkQ quadruple mutants) and RVE (rve8 and rve4;6;8) genes were shown to control circadian rhythms, photomorphogenic responses, and photoperiod-dependent flowering time. Despite the large number of processes controlled by these genes, there are no studies that explore their role in responses to stress. In recent work, we found that lnk mutants were more susceptible than the WT to bacterial infection. Here we analyze the role of the LNK and RVE gene families in both biotic and abiotic stress responses. We perform a meta-analysis of whole transcriptome sequencing RNAseq data from lnk1;2 and rve8 mutants, and RVE8 over-expressive transgenic plants, finding that stress-related genes were enriched among the differentially expressed genes in all mutant backgrounds studied. Also, we found that lnk and rve mutants displayed altered responses to bacterial infection as well as several abiotic stress stimuli when compared to wild-type plants. Our work indicates that members of the LNK and RVE families have both distinctive functions in the control of stress responses, proving to be an essential link to orchestrate light-regulated plant plasticity in response to an ever-changing environment.