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Micro R 828 regulates lignin and H 2 O 2 accumulation in sweet potato on wounding
Author(s) -
Lin JengShane,
Lin ChihChing,
Lin HsinHung,
Chen YuChi,
Jeng ShihTong
Publication year - 2012
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2012.04277.x
Subject(s) - methyl jasmonate , biochemistry , chemistry , microbiology and biotechnology , gene expression , guanosine , jasmonate , biology , gene , arabidopsis , mutant
Summary Micro RNA s (mi RNA s) are small noncoding RNA s which post‐transcriptionally regulate gene expression by directing mRNA cleavage or translational inhibition. mi RNA s play multiple roles in the growth, development and stress responses in plants. However, little is known of the wounding‐responsive mi RNA s and their regulation. Here, we investigated the expression patterns of micro R 828 (mi R 828) on wounding in sweet potato ( I pomoea batatas cv T ainung 57). The expression of mi R 828 was only detected in leaves, and was induced by wounding rather than by ethylene, hydrogen peroxide ( H 2 O 2 ), methyl jasmonate or nitric oxide ( NO ). Moreover, cyclic guanosine monophosphate (c GMP ) was necessary for mi R 828 accumulation in leaves on wounding. Two mi R 828 target candidates, named IbMYB and IbTLD , were obtained by cDNA cloning, and their mRNA cleavage caused by mi R 828 was confirmed by cleavage site mapping, agro‐infiltration and transgenics studies. The reduction in IbMYB and IbTLD expression coincided with the induction of mi R 828, demonstrating that IbMYB and IbTLD might be mi R 828 targets. Furthermore, transgenic sweet potato overexpressing miR828 precursor affected lignin and H 2 O 2 contents. These results showed that cGMP could regulate wounding‐responsive mi R 828, which repressed the expression of IbMYB and IbTLD . Subsequently, lignin and H 2 O 2 were accumulated to participate in defense mechanisms.