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Functionally redundant SHI family genes regulate Arabidopsis gynoecium development in a dose‐dependent manner
Author(s) -
Kuusk Sandra,
Sohlberg Joel J.,
Magnus Eklund D.,
Sundberg Eva
Publication year - 2006
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.2006.02774.x
Subject(s) - arabidopsis , gynoecium , gene , genetics , biology , gene family , computational biology , botany , gene expression , stamen , mutant , pollen
Summary Gene duplication events, and the subsequent functional divergence of duplicates, are believed to be important evolutionary agents, driving morphological diversification. We have studied the structural and functional diversification of members of a plant‐specific gene family in Arabidopsis thaliana by analysing mutant phenotypes, expression patterns and phylogeny. The SHI gene family comprises ten members that encode proteins with a RING finger‐like zinc finger motif. We show that, despite being highly divergent in sequence, except in two conserved regions, many of the SHI ‐related genes are partially redundant in function and synergistically promote gynoecium, stamen and leaf development in Arabidopsis. Gynoecia of the loss‐of‐function sty1‐1 mutant display subtle morphological defects, and, although mutations in the related STY2 , SHI , SRS3 , SRS4 , SRS5 , SRS7 and LRP1 genes have no apparent effect on gynoecium development, the sty1‐1 mutant phenotype is gradually enhanced in double, triple, quadruple and quintuple mutant combinations, suggesting a remarkably extensive functional conservation within the family, which appears to be based on dosage dependency and protection against dominant negative mutations. In multiple mutant lines, all marginal tissues in the apical part of the gynoecium are dramatically reduced or missing, and our data indicate that SHI family members may promote formation of these tissues downstream of the transcriptional co‐repressor LEUNIG (LUG).