Open AccessMiR397b regulates both lignin content and seed number in Arabidopsis via modulating a laccase involved in lignin biosynthesis
Author(s) -
Wang CongYing,
Zhang Shengchun,
Yu Yang,
Luo YuChun,
Liu Qing,
Ju Changliang,
Zhang YuChan,
Qu LiangHu,
Lucas William J.,
Wang Xiaojing,
Chen YueQin
Publication year - 2014
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12222
Subject(s) - laccase , silique , lignin , arabidopsis , biology , inflorescence , gene knockdown , tilling , shoot , biochemistry , botany , gene , enzyme , mutant , genetics
Summary Plant laccase ( LAC ) enzymes belong to the blue copper oxidase family and polymerize monolignols into lignin. Recent studies have established the involvement of micro RNA s in this process; however, physiological functions and regulation of plant laccases remain poorly understood. Here, we show that a laccase gene, LAC 4 , regulated by a micro RNA , miR397b, controls both lignin biosynthesis and seed yield in Arabidopsis. In transgenic plants, overexpression of miR397b ( OX miR397b) reduced lignin deposition. The secondary wall thickness of vessels and the fibres was reduced in the OX miR397b line, and both syringyl and guaiacyl subunits are decreased, leading to weakening of vascular tissues. In contrast, overexpression of miR397b‐resistant laccase m RNA results in an opposite phenotype. Plants overexpressing miR397b develop more than two inflorescence shoots and have an increased silique number and silique length, resulting in higher seed numbers. In addition, enlarged seeds and more seeds are formed in these miR397b overexpression plants. The study suggests that miR397‐mediated development via regulating laccase genes might be a common mechanism in flowering plants and that the modulation of laccase by miR397 may be potential for engineering plant biomass production with less lignin.