干旱胁迫对马铃薯类黄酮和类胡萝卜素合成关键酶基因表达的影响

Effects of Drought on Gene Expressions of Key Enzymes in Carotenoid and Flavonoid Biosynthesis in Potato

利用马铃薯抗旱二倍体材料H145和对干旱敏感二倍体材料H214,通过半定量RT-PCR方法研究了干旱胁迫0、7、10、12、14d时叶片和根系中3-二氢黄酮羟化酶(F3H)基因、黄酮合成酶(FLS)基因和β-胡萝卜素羟化酶1(HYD-1)基因的表达状况。结果表明:干旱胁迫过程中马铃薯品系H145和H214叶片和根系中F3H基因、FLS基因、HYD-1基因的表达量在轻度或中度干旱胁迫下有不同程度的增加,但品系H145在干旱的早期叶片中F3H基因表达量比根系中增加快,并且叶片中FLS基因和HYD-1基因受干旱诱导的表达持续时间比根系中长;品系H214叶片中F3H基因受干旱诱导表达持续的时间比根系中长,在干旱的早期叶片里FLS基因和HYD-1基因表达量没有根系中增加快。说明F3H、FLS和HYD-1基因参与了马铃薯抗旱反应,但不同的品系这些基因起作用的方式可能不同。

The β-carotene hydroxylase-1 （HYD-1）, flavonone-3-hydroxylase （F3H） and flavonol synthase （FLS） are key enzymes in biosynthesis of flavonoid and carotenoid. The transcript levels of genes of these three key enzymes were investigated by semi-quantitative RT-PCR under drought （withholding watering for 0, 7, 10, 12, 14 days respectively） in drought tolerance genotype of diploid H145 and drought susceptive genotype of diploid H214. The results showed that the gene transcript of these three key enzymes was increased in leaves and roots of two genotypes under mild and moderate drought. In the genotype of H145, the transcript level of F3H gene in leaves increased faster than that in roots, and the duration of transcript of FLS ＆ HYD-1 gene in leaves was longer than that in roots under drought stress. In genotype of H214, the duration of transcript of F3H gene in leaves was longer than that in the roots, the transcript level of FLS and HYD-1 gene in leaves increased slower than that in roots under drought stress. The results suggested that the genes of β-carotene hydroxylase-1, flavonone-3-hydroxylase and flavonol synthase were concerned with the drought tolerance in potato, and there might be different acting models of these genes under drought in different genotypes.