102 SAUR-AC1 はブラシノステロイドとオーキシンに共通する早期応答遺伝子である

概要

論文の詳細を見る
Brassinosteroid (BR) has been suggested to interact closely with auxin to regulate plant growth and development. We have demonstrated that many auxin-inducible genes were induced by BR. In this work, we chose SAUR-AC1 gene for further analysis. Arabidopsis BR deficient mutant, det2,was grown under continuous light or darkness for 7 days, then treated with 10 nM brassinolide (BL). The mRNA of SAUR-AC1 was accumulated within 30 min both in light and dark. The data suggest that SAUR-AC1 is the earliest induced gene by BL. Wild type plants (Col-0) was also treated by 10 nM, 100 nM and 1 μM BL or IAA. The induction kinetics by BL was different from auxin. The induction of SAUR-AC1 mRNA treated by BL and IAA was larger than BL of IAA alone. The result indicated that the effect of BL and auxin was synergistic. Transgenic arabidopsis seedlings containing SAUR-AC1 : : GUS fusion gene were treated with BL, and then stained for GUS activity. In light-grown plants, GUS activity was detected in cotyledons and hypocotyl. Similar staining pattern was observed in auxin treatment. GUS staining was reduced by BR-biosynthesis inhibitor, Brz. From these results, it is suggested that the SAUR-AC1 is a shared signaling component in BR- and auxin-signaling pathways, and it functions as an activator to regulate cell elongation in both signaling pathways.
植物化学調節学会の論文
2002-10-31