木薯低温诱导基因MeLTI6A的克隆与序列分析

为了研究木薯(Manihot esculenta Crantz)的抗逆境胁迫机制，从水稻低温诱导及抗旱基因OsLTI6A出发，同源克隆了木薯的抗逆基因MeLIT6A，并对其序列和功能进行了分析研究。MeLIT6A的基因组序列全长为273 bp，其中ORF长度为173 bp，内含子长度为99 bp；编码1个含有57个氨基酸残基的蛋白，含有1个与Pmp3超级家族同源性极高的保守区域。该基因推导蛋白MELTI6A与蓖麻的、拟南芥的、水稻的、玉米的低温诱导蛋白基因6A (LTI6A)的推导蛋白的同源性分别为：89.7%。81.0%、74.1%和87.9%。蛋白功能分类预测MELTI6A是1个非酶类的、疏水性较高的、有2个透膜区域的蛋白，可能有转运蛋白和作为受体蛋白的功能，与拟南芥的AtLTI6A的功能相似。

Cloning and Sequence Analysis of Low Temperature Inducible Gene (MeLTI6A) of Manihot esculenta

In order to research the cassava （Manihot esculenta Crantz） resistant mechanism of adversity stress, the homologue gene of rice OsLTI6A was cloned, based on the cold induced and drought resistant gene MeLTI6A, from cassava. The sequence and function of MeLTI6A was analyzed. MeLIT6A genome full sequence was 273 bp, with which an integrated ORF length was 173 bp, an intron length was 99 bp. MeLIT6A encoded a protein which contained fifty-seven amino acids, and it contained a conserved domain with very high homology of Pmp3 super family. The amino acid sequence of deduced protein MELTI6A was 89.7%. 81.0%, 74.1% and 87.9% identical with the low temperature induced protein gene 6 A （LTI6A）’s deduced proteins of Ricinus communis, Arabidopsis thaliana, Oryza sativa, and Zea mays respectively. Protein function prediction of MELTI6A suggested that it was a nonenzyme protein, had high hydrophobic property and two semipermeable film regions. It may have the function as a protein transporter and receptor, just like the AtLTI6A gene in Arabidopsis.