Altered levels of the Taraxacum kok-saghyz (Russian dandelion) small rubber particle protein, TkSRPP3, result in qualitative and quantitative changes in rubber metabolism
Altered levels of the Taraxacum kok-saghyz (Russian dandelion) small rubber particle protein, TkSRPP3, result in qualitative and quantitative changes in rubber metabolism
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DOI：
10.1016/j.phytochem.2012.04.015
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发表时间：
2012-07-01
期刊：
影响因子：
3.8
通讯作者：
Shintani, David
中科院分区：
文献类型：
--
作者：
Collins-Silva, Jillian;Nural, Aise Taban;Shintani, David
有几种蛋白质已被鉴定并与天然橡胶的生物合成有关，其中小橡胶颗粒蛋白(SRPP)最初在巴西橡胶树中被鉴定为一种与被称为橡胶颗粒的胞质囊泡相关的丰富蛋白质。虽然先前的体外研究表明SRPP在橡胶生物合成中发挥作用，但体内证据缺乏支持这一假说。为了解决这个问题，在蒲公英(俄罗斯蒲公英或TK)中采用了转基因方法来确定SRPP水平的变化是否会影响橡胶的生物合成。在蒲公英橡胶颗粒上发现了三种蒲公英SRPP。最丰富的颗粒相关SRPP，TkSRPP3，表现出与天然橡胶在蒲公英中积累的时空模式一致的表达模式。为了证实TkSRPP3在橡胶生物合成中的作用，利用过表达和RNAi方法改变了TkSRPP3在俄罗斯蒲公英中的表达。与对照相比，TkSRPP3高表达品系的根中橡胶含量略高，而TkSRPP3 RNAi品系的根系橡胶含量显著降低，产生的橡胶分子量显著低于对照。这里的结果不仅提供了TkSRPP蛋白影响蒲公英根中橡胶含量的体内证据，而且它们还表明了TkSRPP蛋白在调节顺-1，4-聚异戊二烯聚合物的分子量方面的功能。(C)2012爱思唯尔有限公司。保留所有权利。
Several proteins have been identified and implicated in natural rubber biosynthesis, one of which, the small rubber particle protein (SRPP), was originally identified in Hevea brasiliensis as an abundant protein associated with cytosolic vesicles known as rubber particles. While previous in vitro studies suggest that SRPP plays a role in rubber biosynthesis, in vivo evidence is lacking to support this hypothesis. To address this issue, a transgene approach was taken in Taraxacum kok-saghyz (Russian dandelion or Tk) to determine if altered SRPP levels would influence rubber biosynthesis. Three dandelion SRPPs were found to be highly abundant on dandelion rubber particles. The most abundant particle associated SRPP, TkSRPP3, showed temporal and spatial patterns of expression consistent with patterns of natural rubber accumulation in dandelion. To confirm its role in rubber biosynthesis, TkSRPP3 expression was altered in Russian dandelion using over-expression and RNAi methods. While TkSRPP3 over-expressing lines had slightly higher levels of rubber in their roots, relative to the control, TkSRPP3 RNAi lines showed significant decreases in root rubber content and produced dramatically lower molecular weight rubber than the control line. Not only do results here provide in vivo evidence of TkSRPP proteins affecting the amount of rubber in dandelion root, but they also suggest a function in regulating the molecular weight of the cis-1, 4-polyisoprene polymer. (C) 2012 Elsevier Ltd. All rights reserved.