Premium
Gene mapping and functional analysis of the novel leaf color gene SiYGL1 in foxtail millet [ Setaria italica (L.) P. Beauv]
Author(s) -
Li Wen,
Tang Sha,
Zhang Shuo,
Shan Jianguo,
Tang Chanjuan,
Chen Qiannan,
Jia Guanqing,
Han Yuanhuai,
Zhi Hui,
Diao Xianmin
Publication year - 2016
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/ppl.12405
Subject(s) - setaria , mutant , biology , setaria viridis , genetics , gene , chloroplast , forward genetics , functional genomics , wild type , phenotype , gene expression , positional cloning , botany , genome , genomics , weed
Setaria italica and its wild ancestor Setaria viridis are emerging as model systems for genetics and functional genomics research. However, few systematic gene mapping or functional analyses have been reported in these promising C4 models. We herein isolated the yellow‐green leaf mutant ( siygl1 ) in S. italica using forward genetics approaches. Map‐based cloning revealed that SiYGL1 , which is a recessive nuclear gene encoding a magnesium‐chelatase D subunit ( CHLD ), is responsible for the mutant phenotype. A single Phe to Leu amino acid change occurring near the ATPase ‐conserved domain resulted in decreased chlorophyll (Chl) accumulation and modified chloroplast ultrastructure. However, the mutation enhanced the light‐use efficiency of the siygl1 mutant, suggesting that the mutated CHLD protein does not completely lose its original activity, but instead, gains novel features. A transcriptional analysis of Chl a oxygenase revealed that there is a strong negative feedback control of Chl b biosynthesis in S. italica . The SiYGL1 mRNA was expressed in all examined tissues, with higher expression observed in the leaves. Comparison of gene expression profiles in wild‐type and siygl1 mutant plants indicated that SiYGL1 regulates a subset of genes involved in photosynthesis ( rbcL and LHCB1 ), thylakoid development ( DEG2 ) and chloroplast signaling ( SRP54CP ). These results provide information regarding the mutant phenotype at the transcriptional level. This study demonstrated that the genetic material of a Setaria species could be ideal for gene discovery investigations using forward genetics approaches and may help to explain the molecular mechanisms associated with leaf color variation.