Modified expression of a carrot small heat shock protein gene, Hsp17.7, results in increased or decreased thermotolerance
Modified expression of a carrot small heat shock protein gene, Hsp17.7, results in increased or decreased thermotolerance
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DOI：
10.1046/j.1365-313x.1999.00581.x
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发表时间：
1999-10-01
期刊：
影响因子：
7.2
通讯作者：
Zimmerman, JL
中科院分区：
文献类型：
--
作者：
Malik, MK;Slovin, JP;Zimmerman, JL
我们已经确定编码 Hsp17.7 的一个小的热休克蛋白基因在胡萝卜细胞和植物抵抗热应激的能力中发挥着重要作用。产生了转基因细胞和再生植物，其中胡萝卜Hsp17.7基因要么组成型表达（表示为CaS系），要么表达为热诱导反义RNA（表示为AH系）。耐热性测量表明，CaS 品系比载体对照更耐热，而 AH 反义品系比载体对照耐热性较差。 RNA 分析表明，在热休克之前，在 CaS 细胞中可检测到 Hsp17.7 mRNA，但含量不高，但在载体对照细胞中则不然。相反，反义细胞的RNA分析表明，热休克后，AH细胞中Hsp17.7的mRNA量比载体对照中的丰度稍低。对 CaS 细胞中蛋白质合成的分析并未表明在 23°C 时 Hsp17.7 或任何小 Hsp 的大量合成或积累。然而，在最耐热的细胞系中，在更极端的热激（42°C）下，蛋白质合成保持在比其他细胞系更高的速率。相反，反义 AH 细胞显示许多大大小小的 Hsp 合成减少。这些结果表明，Hsp17.7 基因在胡萝卜的耐热性中发挥着关键作用，尽管这一作用尚不清楚。这首次证明了通过操纵单个基因的表达来增加和减少耐热性的能力。
We have determined that one small heat shock protein gene, encoding Hsp17.7, plays an important role in the ability of carrot cells and plants to survive thermal stress. Transgenic cells and regenerated plants were generated in which the carrot Hsp17.7 gene was either constitutively expressed (denoted CaS lines) or expressed as a heat inducible antisense RNA (denoted AH lines). Thermotolerance measurements demonstrated that CaS lines were more thermotolerant than vector controls and AH antisense lines were less thermotolerant than vector controls. RNA analysis demonstrated that Hsp17.7 mRNA was detectable, but not abundant, prior to heat shock in CaS cells, but not in vector control cells. Conversely, RNA analysis of antisense cells showed that, after heat shock, the amounts of mRNA for Hsp17.7 was moderately less abundant in AH cells than in vector controls. Analysis of protein synthesis in CaS cells did not indicate substantial synthesis or accumulation of Hsp17.7, or any small Hsp, at 23 degrees C. However, in the most thermotolerant line, protein synthesis was maintained at a higher rate than in other cell lines at a more extreme heat shock (42 degrees C). In contrast, antisense AH cells showed reduced synthesis of many Hsp, large and small. These results suggest that the Hsp17.7 gene plays a critical, although as yet not understood, role in thermotolerance in carrot. This represents the first demonstration of the ability to both increase and decrease thermotolerance by the manipulation of expression of a single gene.