柱花草苯丙氨酸解氨酶（SgPALs）对生物胁迫与非生物胁迫的响应

本研究以热研2号柱花草为材料,分析其苯丙氨酸解氨酶（PAL）活性、总酚含量、类黄酮含量、总抗氧化能力和SgPALs基因表达模式对生物胁迫（炭疽菌侵染）与非生物胁迫（干旱和盐胁迫）的响应。结果表明,在3种胁迫处理下,柱花草不同组织部位的PAL活性增加18.58%~123.56%,且叶片的总酚含量、类黄酮含量和总抗氧化能力分别增加65.11%~68.00%、51.00%~76.87%和83.00%~262.08%,差异显著。在干旱和盐胁迫处理下,根系的总酚含量、类黄酮含量和总抗氧化能力也显著提高43.77%~51.12%、45.46%~45.98%和60.45%~97.89%。随后对SgPALs的表达模式分析表明,除SgPAL4外,其他3个SgPALs受炭疽菌侵染诱导上调表达;在干旱胁迫下,根系中4个SgPALs均增强表达,但叶片中仅SgPAL1和SgPAL4上调表达;在盐胁迫下,根系中4个SgPALs也都上调表达,叶片中除SgPAL3下调表达外,其他3个SgPALs增强表达。综上所述,在遭受生物胁迫和非生物胁迫时,柱花草中的SgPALs基因表达及PAL酶活性升高,伴随着总酚与类黄酮含量的同步升高,表明其对环境胁迫的抗性升高。

Response of Phenylpropane Ammonia-lyase on Biotic and Abiotic Stress in Stylosanthes

Changes in PAL activity, total phenol and flavonoid content, total antioxidant capacity and SgPALs expression pattern were analyzed to study the responses of Stylosanthes guianensis cv. Reyan2 to biotic (infectied by Colletotrichum gloeosporioides) and abiotic (drought and salt) stresses. PAL activity increased by 18.58%-123.56% in different tissues under treatments of the three different stresses. The total phenol and total flavonoid content, and the total antioxidant capacity significantly increased by 65.11%-68.00%, 51.00%-76.87% and 83.00%-262.08%, respectively, in the leaf by pathogen infection, drought and salt stress, and similarly increased by 43.77%-51.12%, 45.46%-45.98% and 60.45%-97.89%, respectively, in the root by pathogen infection, drought and salt stress. PAL gene expression patterns showed that the cloned SgPALs genes, except SgPAL4, were up-regulated by anthrax infection in the leaf. The SgPALs genes were up-regulated by drought stress in the root while only SgPAL1 and SgPAL4 were up-regulated in the leaf. Under salt stress, the SgPALs genes were up-regulated in the root, while the SgPALs genes, except SgPAL3, were down-regulated in the leaf.