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以不同浓度的PEG-6000溶液模拟干旱胁迫条件,研究转TPS1基因玉米植株抗旱性增强的原因。结果表明,随着干旱胁迫加重,野生型和转基因玉米植株的叶片相对含水量和耐旱系数逐渐降低;但转基因玉米植株叶片相对含水量和耐旱系数高于野生型,表明转基因玉米植株比野生型更抗旱。同时随着干旱加重,野生型和转基因玉米植株花青素含量也随之增加,且转基因玉米植株的花青素含量高于野生型。相关性分析表明,花青素含量与转基因玉米抗旱性增强显著相关。干旱胁迫前,转TPS1基因玉米植株花青素含量与野生型植株无显著差异,而在10%PEG-6000模拟干旱胁迫条件下,转TPS1基因玉米植株根、茎、叶的花青素含量极显著高于野生型,分别是野生型的8.5、5.4和1.8倍。分析调控花青素合成基因的相对表达量结果表明,正调控基因PL1、R1和PAC1在转基因植株根、茎、叶中表达均上调,而负调控基因c1-I-2K1在根、茎、叶中表达下调。表明TPS1基因的表达影响花青素合成调控基因的表达促进花青素积累,进而提高植株抗旱性。此外,干旱胁迫后,转基因植株的CAT活性比野生型高56.3%,MDA含量比野生型低36.7%,说明TPS1基因的表达提高了玉米抗氧化能力。
Different concentrations of PEG-6000 solution were used to simulate the drought stress conditions to study the reason for the enhanced drought resistance of TPS1 transgenic maize plants. The results showed that the leaf relative water content and drought tolerance coefficient of wild-type and transgenic maize plants decreased gradually with the increase of drought stress. However, the relative water content and drought-resistance coefficient of transgenic maize leaves were higher than those of wild type plants, More drought-type. At the same time, with the increase of drought, the content of anthocyanin in wild-type and transgenic corn plants also increased, and the content of anthocyanin in transgenic corn plants was higher than wild type. Correlation analysis showed that anthocyanin content was significantly correlated with enhanced drought resistance in transgenic maize. Before drought stress, the content of anthocyanin in transgenic TPS1 maize plants was not significantly different from that in wild type plants. Under the conditions of 10% PEG-6000 simulated drought stress, the content of anthocyanin in roots, stems and leaves of transgenic TPS1 maize Significantly higher than the wild-type, respectively 8.5, 5.4 and 1.8 times the wild-type. The results showed that the positive regulatory genes PL1, R1 and PAC1 were upregulated in the roots, stems and leaves of transgenic plants, while the negative control gene c1-I-2K1 was up-regulated in roots, stems and leaves In the expression down. The results indicated that the expression of TPS1 gene affected the expression of anthocyanin biosynthesis genes and promoted the accumulation of anthocyanins, which in turn increased the drought resistance of plants. In addition, CAT activity of transgenic plants was 56.3% higher than wild type and MDA content was 36.7% lower than that of wild type after drought stress, indicating that the expression of TPS1 gene enhanced the antioxidant capacity of maize.