首页|Map-Based Cloning of zb7 Encoding an IPP and DMAPP Synthase in the MEP Pathway of Maize

Map-Based Cloning of zb7 Encoding an IPP and DMAPP Synthase in the MEP Pathway of Maize

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IspH is a key enzyme in the last step of the methyI-D-erythritol-4-phosphate (MEP) pathway.Loss of function of IspH can often result in complete yellow or albino phenotype in many plants.Here,we report the characterization of a recessive mutant of maize,zebra7 (zb7),showing transverse green/yellow striped leaves in young plants.The yellow bands of the mutant have decreased levels of chlorophylls and carotenoids with delayed chloroplast development.Low temperature suppressed mutant phenotype,while alternate light/dark cycle or high temperature enlarged the yellow section.Map-based cloning demonstrated that zb7 encodes the IspH protein with a mis-sense mutation in a conserved region.Transgenic silencing of Zb7 in maize resulted in complete albino plantlets that are aborted in a few weeks,confirming that Zb7 is important in the early stages of maize chloroplast development.Zb7 is constitutively expressed and its expression subject to a 16-h light/8-h dark cycle regulation.Our results suggest that the less effective or unstable IspH in zb7 mutant,together with its diurnal expression,are mechanistically accounted for the zebra phenotype.The increased IspH mRNA in the leaves of zb7 at the late development stage may explain the restoration of mutant phenotype in mature stages.

zb7 mutantchloroplastIspHRNAimap-based cloning

Xiao-Min Lu、Xiao-Jiao Hu、Yuan-Zeng Zhao、Wei-Bin Song、Mei Zhang、Zong-Liang Chen、Wei Chen、Yong-Bin Dong、Zhen-Hua Wang、Jin-Sheng Lai

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State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, PR China

Henan Academy of Agricultural Science, Zhengzhou, 450002, PR China

Department of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, PR China

This work was supported by the National Basic Research Program of China (973 Program)国家高技术研究发展计划(863计划)

2009CB1184002010AA10A106

2012

分子植物(英文版)
中科院上海生命科学研究院植物生理生态所 中国植物生理学会

分子植物(英文版)

CSTPCDCSCDSCI
影响因子:0.659
ISSN:1674-2052
年,卷(期):2012.5(5)
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