氯化血红素诱导烟草抵御碱胁迫的初步研究

摘要

This study introduced the influence of hemin in tobacco growth and physiological characteristics under alkali stress and attempted to explore the mechanism through antioxidant system, osmotic adjustment system, ion contents and related gene expression. Results showed that 1 μmol/L hemin and 2 μmol/L hemin could promote growth, and increase fresh weight, root length and relative water content of tobacco under alkali stress. Hemin could reduce malondialdehyde (MDA) content and relative conductivity, and increase superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbic acid reductase (APX) activity and contents of chlorophyll, carotenoid, proline, soluble sugar, soluble protein and improve root activity. Hemin treatment could reduce Na+ accumulation and increase absorption of K+, Ca2+, Mg2+. Real-time relative quantitative PCR results showed that hemin could induce NtPDR1, NtPDR3, NtNAC and NtGSH1 gene expression. The above results indicated that hemin could relieve the damage of tobacco under alkali stress result from combined effects of stimulating antioxidant and osmotic regulation system, strengthening ion transport and adjusting related genes expression.%为研究外源氯化血红素(hemin)处理对碱胁迫下烟株生长和生理特性的影响,以云烟87为材料,从抗氧化系统、渗透调节系统、离子含量以及相关基因表达来探讨hemin对烟草抗碱的作用机理.结果表明:外源施加1 μmol/L hemin和2 μmol/L hemin能促进碱胁迫下烟株的生长;降低丙二醛(MDA)含量和相对电导率,提高超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸还原酶(APX)活力,同时增加叶绿素、脯氨酸、可溶性糖、可溶性蛋白等含量,提高根系活力;还可以减少烟株体内Na+积累,增加K+、Ca2+、Mg2+吸收.相对定量PCR结果表明,hemin处理后NtPDR1、NtPDR3、NtNAC和NtGSH1基因表达上调.综上所述,hemin缓解烟株碱胁迫伤害是激发抗氧化系统和渗透调节系统、加强离子转运及调节相关基因表达综合作用的结果.