White‐Green Leaf Gene Encoding Protochlorophyllide Oxidoreductase B Is Involved in Chlorophyll Synthesis of Rice

• DOI: 10.2135/cropsci2014.03.0185
• Publication Date: 2014-12-22T14:01:32Z
• Authors: Shu‐Jing Kang; Yun‐Xia Fang; Guo‐Xing Zou; Ban‐Pu Ruan; Juan Zhao; Guo‐Jun Dong; Mei‐Xian Yan; Zhen‐Yu Gao; Li Zhu
• Keywords: Protochlorophyllide; Variegation (histology)

ABSTRACT A white‐green leaf ( wgl1 ) mutant, derived from Nipponbare (NIP) Oryza sativa L. ssp. japonica treated with ethyl methanesulfonate, exhibited variegation and brown necrotic lesions during old elongation. However, the mutant gradually changed in color to light green at later stages of development field‐grown plants. Pigment investigation showed that change is associated chlorophyll (Chl) carotenoid content reduction. Electron microscopic analysis chloroplasts revealed a decrease number loss grana stacks. In addition, prolamellar bodies etioplasts were smaller than NIP concentric‐rings stromal thylakoids 7‐d‐old darkness‐grown seedlings. As result, chloroplast was impaired. Genetic results phenotype caused by recessive mutations single nuclear gene. Map‐based cloning complementation tests WGL1 , located on chromosome 10, encodes OsPORB (Os10 g35370), one two isoforms nicotinamide adenine dinucleotide 2′‐phosphate reduced tetrasodium salt: protochlorophyllide oxidoreductase (POR). Real‐time polymerase chain reaction β ‐Glucuronidase reporter highest expression levels observed flag leaves, whereas root almost undetected. These indicate involved Chl biosynthesis rice.