耐熱番茄與不耐熱番茄中SAM3與SUS3基因之分析及比較

Characterization and Comparison of SAM3 and SUS3 Genes between Heat-Tolerant and Heat-Sensitive tomatoes (Solanum lycopersicum)

王怡潔(Yi-Chieh Wang)

指導教授 ： 鄭石通

國立臺灣大學/生命科學院/植物科學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.10497

摘要

番茄原產於溫帶地區，經過歐美國家長期引種與品種改良， 使它成為一個遍佈世界的重要茄果類蔬菜。番茄生育期間對於溫度十分敏感，其生長適溫為晝溫20~26℃，夜溫15~20℃，夜溫20℃被認為是溫帶國家番茄品種的栽培臨界溫度。而台灣高溫多濕的氣候，常使番茄生長不良，結果率降低，使得栽培季節僅限於秋冬季，為提升夏季番茄產量，因此針對耐熱番茄雄蕊進行分子層面的研究。本實驗中証實在夜溫超過20℃的環境下，番茄之花粉存活率降低及花粉管萌發生長受到抑制，隨即採用亞蔬中心所提供之耐熱番茄品系CL5915-206-220分離出番茄雄蕊在高溫下受到大量誘導的基因，其中挑選Sucrose synthase及S-adenosyl-methionine synthetase (SAM synthase)兩基因對番茄進行轉殖，轉殖的方式是以Erwinia carotovora取代抗生素作為篩選的方式，可免除轉殖番茄中帶有抗抗生素基因的疑慮。本實驗中得到於不耐熱番茄L4783中過量表現SAM synthase基因之轉植株，並且以花粉存活率及花粉管萌發生長率觀測期花粉耐熱性，發現轉植番茄的花粉存活率及花粉管萌發生長率均較不耐熱番茄L4783為高，可見SAM synthase基因的過量表現可能可以增加番茄的耐熱性質。

關鍵字

耐熱番茄 ； 不耐熱番茄 ； 熱逆境 ； 花粉

並列摘要

Impairment of tomato pollen during anther development by elevated temperature contributes to decreased fruit set. In this study, I found that continuous exposure of tomato to high temperatures (day/ night temperature of 35/ 30 and 30/ 25 °C) decreased pollen activity and reduced of pollen grain germination. To isolate these heat-induced genes affecting pollen viability, suppression subtractive hybridization was used to isolate cDNA fragments from heat-tolerant tomato anther. In these heat-induced genes, sucrose synthase (SUS3) and S-adenosyl-methionine synthetase (SAM3), were chosen for further study. Real-time PCR confirmed that these two genes, SUS3 and SAM3, were induced by high temperature in the heat-tolerant tomato. Furthermore, transgenic tomato expressing SUS3 or SAM3 was used to verify the functions of these genes in protecting tomato from heat. Transgenic plants were produced by Agrobacterium tumefaciens with pCAMBIA-1390AP, which contains sweet pepper ferredoxin-like protein, and Erwinia carotovora was used as the selection agent. Transgenic tomato L4783 containing the 35S::SAM3 shows higher pollen viability and pollen tube germination rate than wild-type L4783 does. These results may point out that tomato with over-expression of SAM3 may allow tomato to increase its fruit set in tropical weather.

並列關鍵字

SAM3 ； SUS3

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