外源松柏醛和芥子醛影响棉纤维苯丙烷代谢途径基因表达及生长

Effect on Exogenous Coniferyl Aldehyde and Sinapyl Aldehyde on Expressions of Genes Involved in the Phenylpropanoid Pathway and Fiber Development in Cotton

利用棉花胚珠离体培养和半定量RT-PCR及数字化图像处理技术,通过体外饲喂不同浓度苯丙烷代谢途径中间代谢物松柏醛(CA)和芥子醛(SA)来研究在棉花纤维发育过程中苯丙烷代谢关键中间产物对棉花纤维发育的影响。结果表明,在离体培养棉纤维中,不同浓度(100μmol.L-1、200μmol.L-1)外源松柏醛(CA)和芥子醛(SA)不但诱导了以CA和SA为底物的基因产物表达量增加,也诱导了苯丙烷代谢途径上游基因产物的表达量增加,且高浓度(200μmol.L-1)诱导的表达量高于低浓度(100μmol.L-1),芥子醛高于松柏醛;对GhEx-pansin1的表达和纤维生长均有抑制作用,且高浓度(200μmol.L-1)抑制作用更加明显,芥子醛抑制作用大于松柏醛。

We determined the effect of applying exogenous coniferaldehyde（CA） and sinapaldehyde（SA） on gene expression and cotton fiber development. The experimental materials consisted of cotton ovules in vitro. Changes in gene expression and fiber development in response to the various treatments were determined by semi-quantitative reverse transcription-polymerase chain reaction and image digitization analyses, respectively. Compared with ovules in the control, ovules treated with CA or SA at 100 and 200 Ixmol. L-t showed increased expressions of the gene encoding cinnamyl alcohol dehydrogenase（CAD）, which catalyzes phenylpropanoid synthesis. They also showed increased expressions of genes upstream in the phenylpropanoid pathway, includ- ing PAL, which encodes phenylalanine ammonia lyase, C4H, which encodes cinnamate-4-hydroxylase, COMT, which encodes caffeic acid O-methyltransferase, CCoAOMT, which encodes caffeoyl-CoA-3-O-methyltransferase, and CCR, which encodes cinnamoyl-CoA reductase. High concentrations of CA and SA（200 μmol. L-1） induced greater levels of gene expression than did the low concentrations（100 μmol. L-l）. SA induced higher gene expression levels than did CA. Both CA and SA suppressed ex- pression of Ghexpansinl and fiber growth; higher concentrations（200 μmol. L-1） caused greater inhibition, and SA was more in- hibitory than CA.