Molecular cloning and expression analysis of duplicated polyphenol oxidase genes reveal their functional differentiations in sorghum
Molecular cloning and expression analysis of duplicated polyphenol oxidase genes reveal their functional differentiations in sorghum
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重复多酚氧化酶基因的分子克隆和表达分析揭示了它们在高粱中的功能差异
DOI：
10.1016/j.plantsci.2017.07.002
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发表时间：
2017
期刊：
影响因子：
5.2
通讯作者：
Zou GH
中科院分区：
文献类型：
--
作者：
Yan Song;Li Sujuan;Zhai Guowei;Shao Jianfeng;Tao Yuezhi;Zou Guihua;Yan Song;Zhu Shan;Huang Renliang;Lu Ping;Deng Hui;Zou GH
多酚氧化酶（PPO）被认为在植物生长、繁殖和抵抗病原体和害虫中起作用。PPO引起谷物中谷粒的布朗宁。本研究利用重组自交系群体对高粱籽粒酚色反应（PHR）进行了遗传定位。SSR标记SM 06072和Xtxp 176在第6染色体上只检测到一个位点。在定位区域内发现并克隆了两个连锁的正向同源基因Sb06PPO1和Sb06PPO2。以PHR阴性的水稻品种日本晴为材料进行的转化试验表明，LTR 108的Sb06 PPO1和两个品种的Sb06 PPO2等位基因可以互补日本晴，而654的Sb06 PPO1不能互补。实时荧光定量PCR（qPCR）结果表明，Sb06PPO1和Sb06PPO2的功能是双向的，Sb06PPO1主要在开花前的幼穗中表达。Sb06PPO2在开花穗中有较强的表达，尤其是在灌浆期的谷壳和枝条中。此外，外源阿坝和盐对Sb06 PPO1的表达有显著上调作用，而对Sb06 PPO2的表达无显著影响，进一步证明了两个基因之间的功能差异。
Polyphenol oxidase(PPO) is believed to play a role in plant growth, reproduction, and resistance to pathogens and pests. PPO causes browning of grains in cereals. In this study, genetic mapping of sorghum grain for phenol color reaction (PHR) was performed using a recombinant inbred line population. Only one locus was detected between SSR markers SM06072 and Xtxp176 on chromosome 6. Two linked orthologous genes (Sb06PPO1andSb06PPO2) within the mapped region were discovered and cloned. Transformation experiments using Nipponbare (a PHR negative rice cultivar) showed thatSb06PPO1from LTR108 and twoSb06PPO2alleles from both varieties could complement Nipponbare, whereasSb06PPO1from 654 could not. Subsequent quantitative real-time PCR (qPCR) experiments showed thatSb06PPO1andSb06PPO2functioned diversely,Sb06PPO1was mainly expressed in young panicles before flowering. Sb06PPO2 was strongly expressed in flowering panicles, especially in hulls and branches at filling stage. Moreover, the expression ofSb06PPO1was found to be significantly up-regulated by exogenous ABA and salt, whereasSb06PPO2was not changed significantly, further demonstrating functional differentiation between the two genes.