HOMEOBOX PROTEIN52 Mediates the Crosstalk between Ethylene and Auxin Signaling during Primary Root Elongation by Modulating Auxin Transport-Related Gene Expression

摘要: The gaseous hormone ethylene participates in many physiological processes plants. Ethylene-inhibited root elongation involves PIN-FORMED2 (PIN2)-mediated basipetal auxin transport, but the molecular mechanisms underlying regulation of PIN2 function by (and therefore distribution) are poorly understood. Here, we report that plant-specific and ethylene-responsive HD-Zip gene HB52 is involved ethylene-mediated inhibition primary Arabidopsis thaliana. Biochemical genetic analyses demonstrated responsive acts downstream ETHYLENE-INSENSITIVE3 (EIN3). knockdown mutants displayed an ethylene-insensitive phenotype during elongation, while its overexpression resulted short roots, as observed ethylene-treated In addition, distribution gravitropism were impaired lines. Consistent with these findings, vitro vivo binding experiments showed regulates expression transport-related genes, including PIN2, WAVY ROOT GROWTH1 (WAG1), WAG2 physically to their promoter regions. These findings suggest functions modulating transport components EIN3, revealing a mechanism which important node crosstalk between signaling plant growth development.