四种叶片防御酶活性与辣椒对疫病抗性的关系

Relationship Between the Activity of Four Defense Enzymes in Leaf and Phytophthora-resistant of Pepper

以对辣椒疫霉菌3号生理小种具有不同抗性的辣椒近等基因系为试材,测定了不同抗性品系接菌后β?1,3-葡聚糖酶、几丁质酶、PAL、POD活性的变化情况,研究了上述4种叶片防御酶活性与辣椒对疫病抗性的关系。结果表明:辣椒疫霉菌能诱导辣椒叶片中上述4种防御酶的活性增强,但4种酶在积累速度和幅度上抗病品系和感病品系有显著的差异。接菌后高抗品系β?1,3-葡聚糖酶、几丁质酶、PAL、POD活性达到峰值时酶活变化率分别是164.4%、99.1%、173.7%、107.6%;而感病品系的酶活变化率分别是91.8%、48.1%、93.1%、64.0%,与感病品系相比,高抗品系的4种酶活性不仅升高的速度快、幅度大,且高活性维持时间长,中抗品系的4种酶活性介于二者之间。在抗病品系中,β?1,3-葡聚糖酶的酶活变化率是几丁质酶的1.66倍,PAL的酶活变化率是POD的1.61倍。在离体培养条件下观察了β?1,3-葡聚糖酶和几丁质酶粗酶液对辣椒疫霉菌的菌丝生长和孢子囊形成的抑制作用,与对照相比,β?1,3-葡聚糖酶粗酶液抑制作用明显,而几丁质酶粗酶液抑制作用不明显。

Taking three near-isogenie lines with different phytophthora resistance as the experimental material, the activities of four enzymes（β-1,3-glucanase,chitinase,PAL, POD） were detected after induced by race 3 of Phytophthora capsici. The relationship between the activity of four defense enzymes in leaf and phytophthora-resistant of pepper was studied. The results showed that the activities of four defense enzymes in pepper% leaves were increased by infection of Phytophthora capsici, the rate of enzyme activity for β-1,3-glacanase, chitinase, PAL, POD in resistant lines after infection of Phytophthora capsici was 164. 4 %, 99. 1%, 173. 7 %, 107. 6 % ~ but in susceptible lines was 91.8 %, 48. 1%, 93. 1%, 64. 0% ,the increase in activities was faster and higher,and lasted longer in a resistant lines than that in susceptible lines. The activities of enzymes in mid-resistant lines were between two of above. The results suggested that β-1,3-glacanase, chitinase,PAL and POD could be induced by Phytophthora capsici and the relationship between the activities of the four enzymes and the resistance of pepper was positive. In the resistant line,the rate of enzyme activity for β-1,3-glacanase was 1. 66 times higher than chitinase;PAL was 1.61 times higher than POD. The inhibition of β-1,3-glacanase and chitinase to mycelia growth and sporangia formation were observed. β-1,3-glacanase was significantly higher than that of control, chitinase showed no clear inhibition to Phytophthora capsici.