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XIAO is involved in the control of organ size by contributing to the regulation of signaling and homeostasis of brassinosteroids and cell cycling in rice
Author(s) -
Jiang Yunhe,
Bao Liang,
Jeong SoYoon,
Kim SeongKi,
Xu Caiguo,
Li Xianghua,
Zhang Qifa
Publication year - 2012
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2011.04877.x
Subject(s) - cycling , microbiology and biotechnology , homeostasis , rapid cycling , biology , neuroscience , geography , cognition , archaeology , bipolar disorder
Summary Organ size is determined by cell number and size, and involves two fundamental processes: cell proliferation and cell expansion. Although several plant hormones are known to play critical roles in shaping organ size by regulating the cell cycle, it is not known whether brassinosteroids (BRs) are also involved in regulating cell division. Here we identified a rice T‐DNA insertion mutant for organ size, referred to as xiao , that displays dwarfism and erect leaves, typical BR‐related phenotypes, together with reduced seed setting. XIAO is predicted to encode an LRR kinase. The small stature of the xiao mutant resulted from reduced organ sizes due to decreased cell numbers resulting from reduced cell division rate, as supported by the observed co‐expression of XIAO with a number of genes involved in cell cycling. The xiao mutant displayed a tissue‐specific enhanced BR response and greatly reduced BR contents at the whole‐plant level. These results indicated that XIAO is a regulator of BR signaling and cell division. Thus, XIAO may provide a possible connection between BRs and cell‐cycle regulation in controlling organ growth.