Manipulation of strawberry fruit softening by antisense expression of a pectate lyase gene
Manipulation of strawberry fruit softening by antisense expression of a pectate lyase gene
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DOI：
10.1104/pp.010671
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发表时间：
2002-02-01
期刊：
影响因子：
7.4
通讯作者：
Mercado, JA
中科院分区：
文献类型：
--
作者：
Jiménez-Bermúdez, S;Redondo-Nevado, J;Mercado, JA
草莓(Fragaria X ananassa，Duch.，cv Chandler)是一种软质水果，采后寿命短，主要原因是质地坚硬。为了控制草莓果实软化，我们获得了在35S启动子控制下整合了草莓果胶裂解酶基因反义序列的转基因植株。获得了41个独立的转基因株系(APEL系)，在温室中进行了农艺性状分析，并与对照、未转化植株和转化pGUSINT的转基因株系进行了比较。在41个Apel品系中，有33个品系的总产量显著下降。在盛熟期，果实的颜色、大小、形状和重量与对照无明显差异。然而，在大多数Apel品系中，成熟的水果明显比对照组坚硬。选择了6个Apel品系进行进一步分析。在所有这些品系中，成熟果实中果胶裂解酶基因的表达比对照低30%，其中3个品系的果胶裂解酶基因表达完全被抑制。从成熟的杏仁果实中分离出的细胞壁物质的体外膨胀程度和离子结合果胶的量都低于对照果实。对果实发育的三个不同阶段(绿色、白色和红色)的硬度分析表明，阿佩尔果实从白色过渡到红色阶段的软化降幅最大。阿佩尔果实采后软化程度也有所减弱。我们的结果表明，果胶裂解酶基因是改良草莓果实软化的一个很好的生物技术候选基因。
Strawberry (Fragaria X ananassa, Duch., cv Chandler) is a soft fruit with a short postharvest life, mainly due to a rapid lost of firm texture. To control the strawberry fruit softening, we obtained transgenic plants that incorporate an antisense sequence of a strawberry pectate lyase gene under the control of the 35S promoter. Forty-one independent transgenic lines (Apel lines) were obtained, propagated in the greenhouse for agronomical analysis, and compared with control plants, non-transformed plants, and transgenic lines transformed with the pGUSINT plasmid. Total yield was significantly reduced in 33 of the 41 Apel lines. At the stage of full ripen, no differences in color, size, shape, and weight were observed between Apel and control fruit. However, in most of the Apel lines, ripened fruits were significantly firmer than controls. Six Apel lines were selected for further analysis. In all these lines, the pectate lyase gene expression in ripened fruit was 30% lower than in control, being totally suppressed in three of them. Cell wall material isolated from ripened Apel fruit showed a lower degree of in vitro swelling and a lower amount of ionically bound pectins than control fruit. An analysis of firmness at three different stages of fruit development (green, white, and red) showed that the highest reduction of softening in Apel fruit occurred during the transition from the white to the red stage. The postharvest softening of Apel fruit was also diminished. Our results indicate that pectate lyase gene is an excellent candidate for biotechnological improvement of fruit softening in strawberry.