通过转化脂肪酸去饱和酶基因AcoFAD2提高菠萝植株的抗寒能力

Improvement Pineapple Plant’s Tolerance to Cold by Transforming Fatty Acid Desaturase Gene AcoFAD2

为培育抗寒菠萝新品种,本研究通过比较菠萝脂肪酸去饱和酶基因序列和拟南芥脂肪酸去饱和酶基因序列,筛选获得目标基因AcoFAD2;通过农杆菌转化菠萝‘台农17’获得过表达AcoFAD2转基因植株TN17FAD2-3;转基因植株和对照在低温条件下进行培养,鉴定转基因植株和对照的不饱和脂肪酸含量及抗寒能力。结果发现组培苗在7℃条件下处理5 d然后转入26℃生长一周,TN17FAD2-3第四片叶坏死比例为(5±1)%,只转化空载体的对照TN17-EV第四片叶坏死比例为(97±2)%。组培苗在7℃条件下生长5 d,然后转入26℃生长15 d。TN17FAD2-3第二片叶叶面积为(2.15±0.2) cm^(2),TN17-EV第二片叶叶面积为(0.06±0.01) cm^(2)。TN17FAD2-3的叶片不饱和脂肪酸含量(16:3+18:3)为(77.5±0.7)%,对照TN17-EV叶片不饱和脂肪酸(16:3+18:3)含量为(58.6±0.8)%。TN17FAD2-3的叶片不饱和脂肪酸含量高于只转化空载体的对照TN17-EV。低温条件下,TN17FAD2-3比TN17-EV生长快,TN17FAD2-3株系比TN17-EV具有更高的抗寒性,载体UBI-pCAMBIA1301不能提高菠萝植株的抗寒能力,通过转化脂肪酸去饱和酶基因AcoFAD2能够提高菠萝植株的抗寒性能,本研究为快速培育抗寒菠萝新品种提供理论基础。

To cultivate pineapple varieties with high cold-tolerance, target gene AcoFAD2(fatty acid desaturase)was gotten by comparing Arabidopsis FAD genes and pineapple FAD genes. Transgenic line TN17 FAD2-3 was gotten by coculturing embryogenic callus of ’Tainong17’ pineapple with Agobacterium tumefaciens GV3101 harboring AcoFAD2. Transgenic seedlings and control were cultivated in low temperature. Their unsatured-fattyacid contents and cold tolerance were measured. Results showed that after seedlings were cultivated in 7 ℃ for5 d and in 26 ℃ for 1 week, the ratios of scorch area versus the total area of the fourth leaf from the apex of TN17 FAD2-3 was(5 ±1)%. The ratios of scorch area versus the total area of the fourth leaf from the apex of pineapple seedlings transformed with empty vector(TN17-EV) was(97±2)%. After seedlings were cultivated in 7 ℃for 5 d and in 26 ℃ for 15 d, the area of the second leaf from the apex of TN17 FAD2-3 was(2.15±0.2) cm^(2). The corresponding value of TN17-EV was(0.06±0.01) cm^(2). The content of unsatured fatty acids(16:3+18:3) in leaves of TN17 FAD2-3 was(77.5±0.7) %. The corresponding values of TN17-EV was(58.6±0.8) %. The content of unsatured fatty acids in leaves of TN17 FAD2-3 was higher than that of TN17-EV. In low temperature, TN17 FAD2-3 grew faster than TN17-EV. TN17 FAD2-3 has higher cold-tolerance than TN17-EV. Only transforming the vector UBI-pCAMBIA1301 cannot enhance the cold tolerance of pineapple plants. Overexpressing the gene AcoFAD2 can increase the cold tolerance of pineapple plants. This study provides a theoretical basis for breeding pineapple varieties with high cold tolerance in a short time.