甘蔗茎成熟相关基因的分离与分析

Isolation of Genes Related to Maturation of Sugarcane Internode

随着甘蔗的成熟,甘蔗茎秆中积累的糖分在不断增加,其薄壁细胞的渗透压也在不断增加,这意味着大量与糖分积累和抗逆相关的基因也得到了大量的表达,对这些基因进行分离和鉴定有助于了解甘蔗茎成熟的分子机制。本研究以果蔗品种拔地拉(Badila)的成熟茎节与未成熟茎节为材料,利用抑制差减杂交技术(suppression subtractive hybridization,SSH)构建了甘蔗茎成熟相关基因的差减cDNA文库。挑取200个重组子进行测序,其中与甘蔗茎成熟相关基因片段有22个,包括2个与信号转导相关的cDNA片段,5个转录翻译相关蛋白,2个光合系统蛋白,8个物质能量代谢cDNA片段,抗逆、糖转运相关蛋白5个,另外还有一些片段通过GenBank搜索未发现有相关的同源序列,推测这些片段可能是功能未知的新基因。

With the maturation of sugarcane,sugar content continuous increase in sugarcane intemode. The osmotic pressure of parenchyma cells in sugarcane intemode increase, too. It means lots of genes expressed relevant to the improving of sugarcane content and stress-resistant. Isolation and cloning of these genes is helpful to understand molecular mechanism of sugarcane maturation. The SSH libraries of sugarcane varieties Badila were constructed using RNA from mature sugarcane intemode and immature sugarcane intemode. 200 clones which were obtained from screening of the subtract library were sequenced. It was shown that 22 candidates had been indicated to exert a positive role in maturation of sugarcane, two of them were associated with signal transduction, five of them were as- sociated with transcription and translation, two of them are associated with photosynthetic pro, eight of them were associated with substance and energy metabolism and five of them were associated with sugarcane content and stress-resistant protein. Some cDNA fragments can not be found from the GenBank with the significantly related ho- mologous sequence. To speculate that they may be the new genes of unknown function. It lay a good foundation for improving of sugar content and stress-resistant.