Antisense-mediated depletion of tomato chloroplast omega-3 fatty acid desaturase enhances thermal tolerance
Antisense-mediated depletion of tomato chloroplast omega-3 fatty acid desaturase enhances thermal tolerance
复制标题
DOI：
10.1111/j.1744-7909.2006.00335.x
复制
发表时间：
2006-09-01
影响因子：
11.4
通讯作者：
Meng, Qing-Wei
中科院分区：
文献类型：
--
作者：
Liu, Xun-Yan;Yang, Jing-Hua;Meng, Qing-Wei
分离了叶绿体定位的番茄 (Lycopersicon esculentum Mill.) omega-3 脂肪酸去饱和酶基因 (LeFAD7)，并对其序列、对不同温度的响应以及反义转基因番茄植物中的功能进行了表征。推导的氨基酸序列具有四个富含组氨酸的区域，其中三个区域在整个omega-3脂肪酸去饱和酶基因家族中高度保守。 Southern blotting分析表明LeFAD7由单拷贝基因编码，在番茄基因组中有两个同源基因。 Northern印迹显示LeFAD7在所有器官中表达，并且在叶组织中尤其丰富。同时，叶片中LeFAD7的表达受到冷胁迫（4℃）诱导，但受到高温（45℃）抑制。通过将CaMV35S启动子控制下的反义LeFAD7 DNA整合到基因组中来产生转基因番茄植物。 18:3含量较低的反义转基因植物可以比野生型植物保持更高的最大光化学效率（F-v/F-m）和O-2进化速率。这些结果表明 LeFAD7 基因的沉默减轻了高温应激。 LeFAD7基因沉默导致的18:3低含量与高温胁迫耐受性之间也存在相关性。
A chloroplast-localized tomato (Lycopersicon esculentum Mill.) omega-3 fatty acid desaturase gene (LeFAD7) was isolated and characterized with regard to its sequence, response to various temperatures, and function in antisense transgenic tomato plants. The deduced amino acid sequence had four histidine-rich regions, of which three regions were highly conserved throughout the whole omega-3 fatty acid desaturase gene family. Southern blotting analysis showed that LeFAD7 was encoded by a single copy gene and had two homologous genes in the tomato genome. Northern blot showed that LeFAD7 was expressed in all organs and was especially abundant in leaf tissue. Meanwhile, expression of LeFAD7 was induced by chilling stress (4 degrees C), but was inhibited by high temperature (45 degrees C), in leaves. Transgenic tomato plants were produced by integration of the antisense LeFAD7 DNA under the control of a CaMV35S promoter into the genome. Antisense transgenic plants with lower 18:3 content could maintain a higher maximal photochemical efficiency (F-v/F-m) and O-2 evolution rate than wild-type plants. These results suggested that silence of the LeFAD7 gene alleviated high-temperature stress. There was also a correlation between the low content of 18:3 resulting from silence of the LeFAD7 gene and tolerance to high-temperature stress.