Auxin inhibits chlorophyll accumulation through ARF7-IAA14-mediated repression of chlorophyll biosynthesis genes in Arabidopsis

• DOI: 10.3389/fpls.2023.1172059
• Publication Date: 2023-04-20T20:31:42Z
• Authors: Wei-Gui Luo; Qi-Wen Liang; Yi Su; Chao Huang; Bei-Xin Mo; Yu Yu; Lang-Tao Xiao
• Keywords: Etiolation; Protochlorophyllide

Auxin is a well-known important phytohormone in plant that plays vital roles almost every development process throughout lifecycle. However, the effect of auxin on metabolism chlorophyll, one most pigments involved photosynthesis, was intertwined and underlying mechanism remained to be explored. Here, we found auxin-defective yuc2 yuc6 double mutant displayed dark-green leaf color with higher chlorophyll content than wildtype, suggesting negative regulatory role biosynthesis. The chloroplast number structure mesophyll cells were altered photosynthetic efficiency improved . In addition, level significantly during seedling de-etiolation mutant, decreased dramatically under IAA treatment, confirming inhibitory analyses gene expression mature leaves seedlings suggested suppressed many biosynthesis genes, especially PROTOCHLOROPHYLLIDE OXIDOREDUCTASE A ( PORA ) GENOMES UNCOUPLED 5 GUN5 ). Yeast-one-hybrid luciferase assays demonstrated AUXIN RESPONSE FACTOR 2 (ARF2) ARF7 bind promoter suppress their help INDOLE-3-ACETIC ACID14 (IAA14). Collectively, our research explicitly unraveled direct biosynthesis, provided new insight into interplay between signaling metabolism.