黑粉病菌对薏苡生长及其细胞壁降解酶活性变化的影响

Effects of Ustffagocoic-sbref on Growth and Cell Wall Degrading-enzyme Activity of Coix lacrymajobi

为了解薏苡黑粉病菌的致病性机制,对种子接种黑粉病菌后的发芽率和幼芽生长抑制作用、黑粉病菌在薏苡不同生长期的侵入危害及接种黑粉病菌后薏苡种子分泌产生的角质酶、果胶甲基半乳糖醛酸酶(PMG)、多聚半乳糖酸酶(PG)、β-1,4-内切葡聚糖酶(Cx)和β-葡聚苷酶的活性变化进行测定。结果表明:黑粉病菌对种子的发芽无抑制作用,对幼芽的生长有一定的抑制作用;接种黑粉病菌孢子后,种子发病率为75.7%,而叶片和穗部的发病率都低于10%;病原菌处理种子后,角质酶的活性在6h和12h出现峰值,略高于对照,其余时间角质酶活性与对照差异不明显,且角质酶的含量和活性均较低;细胞壁降解酶的活性测定发现,种子接触黑粉病菌后,果胶甲基半乳糖醛酸酶(PMG)活性与对照的PMG活性差异不显著,且活性的变化率相同;多聚半乳糖酸酶(PG)、β-1,4-内切葡聚糖酶(Cx)和β-葡聚苷酶的活性在24h内迅速升高,达到峰值,之后迅速下降,与健康植株(CK)的活性差异不显著,且变化规律相同。

The activity of cutinase and cell wall degrading enzymes （polymethyl galacturonase PMG, polygalacturonase PG, β-1,4-endoglucanase Cx and β-galactosidase） of Coix lacrymajobi seeds inoculated with Ustffagocoic-sbref was detected to understand the pathogenicity mechanism and study effects of Ustffagocoic-sbref on seed germination rate and bud growth. The results showed that Ustffagocoic-sbref has no inhibition effect on seed germination and a certain inhibition effect on bud growth. The disease rate of Coix lacrymajobi seeds inoculated with Ustffagocoic-sbref is 75.7% but disease rate of Ustffagocoicsbref leaves and spikes is lower than 10%. The cutinase activity of Coix lacrymajobi seeds inoculated Ustffagocoic-sbref reaches the peak value after 6 h and 12 h respectively, slight higher than CK. There is no obvious difference in cutinase activity but the cutinase content and activity both are lower during other time. PMG activity of Coix c lacrymajobi seeds inoculated with Ustffagocoic-sbref is no difference with CK and the variation rate of PMG activity of Coix lacrymajobi seeds inoculated with Ustffagocoic-sbref and CK is the same. The PG, Cx and β-galactosidase activity of Coix lacrymajobi seeds inoculated with Ustffagocoic-sbref reaches the peak rapidly within 24 h, then drops rapidly and finally is no difference with healthy plants of CK.