摘要
研究了茭白(Zizania latifolia Turcz.)受食用黑粉菌(Ustilago esculenta)侵染后的生长、抗氧化特性和叶绿素荧光的变化。结果表明,食用黑粉菌侵染导致植株的株高、叶长、叶宽、叶片厚度、根长、茎鲜重、根鲜重和地上部鲜重下降,但分蘖数提高;同时提高了茭白叶片的抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)、过氧化物酶(POD)、谷胱甘肽还原酶(GR)、超氧化物歧化酶(SOD)的活性和过氧化氢(H2O2)含量,但却引起超氧自由基(O2.-)产生速率和丙二醛(MDA)含量降低。食用黑粉菌侵染提高了叶片的PSⅡ实际光化学效率(ΦPSⅡ)和电子传递速率(ETR),同时降低了非光化学猝灭(NPQ),但对PSⅡ最大光化学量子产量(Fv/Fm)的影响不大。
A smut fungus Ustilago esculenta causes enlargement of infected culms of Zizania latifolia, a perennial aquatic grass. The swollen culm is used as a vegetable in China and some southeastern countries. Interaction between the fungus and the host plant plays a vital role in the enlargement of infected culms. U. esculenta is a biotrophic endophyte that completes its life cycle in host tissues. In our previous studies, we have observed that Z. latifolia plants infected by U. esculenta showed higher net photosynthetic rate and chlorophyll content, which is different from the results obtained after induction by pathogens. However, in this plant-fungus association, detailed biochemical, physiological or morphological changes , and the role of reactive oxygen species （ROS） and their scavenging system as well as photosystem （PS） lI efficiency during this interactive process, have not been studied. To ascertain the actual relationship between U. esculenta and Z. latifolia, we determined the antioxidative system and chlorophyll fluorescence in leaves of Z. latifolia. The experiment was carried out at Zhejiang University, Hangzhou. Z. latifolia plants （cv. ＂Zhejiao No. 2 ＂, a double-harvest variety） were used in this study. There were 16 pots （10 plants each pot） in each treatment. These plants were regularly watered to keep a 10 cm-layer of water above soil. Pesticides were sprayed for the prevention of pests and diseases if needed. In this study, the response of Z. latifolia plants to U. esculenta infection was investigated, and activities of antioxidant enzymes, superoxide radical （O2＇-） formation rate, hydrogen peroxide （H2O2） content, malondialdehyde （MDA） content, and chlorophyll fluorescence were determined. Our results showed that plant height, leaf length, leaf width, leaf thickness, root length, biomass of culm, root and aboveground were reduced, but tiller number was increased by U. esculenta infection. Meanwhile, U. esculenta infection caused increase in activities of ascorbate peroxidase （APX）, catalase （CAT）, peroxidase （POD）, glutathione reductase （GR）, superoxide dismutase （SOD） and H2O2 content, but decrease in O2^- formation rate and MDA content （P〈0.05）. The decrease of O2^- formation rate in U. esculenta infected plants might be due to the higher SOD activity, which transformed O2^- to H2O2 and O2^- In this study, we also observed that quantum efficiency of PS lI （~PSn） and electron transport rate （ETR） were slightly increased （P 〉 0.05 ）, but non-photochemical quenching （NPQ） was decreased by U. esculenta infection （ P 〉 0.05 ）. It is observed that maximum quantum efficiency of PS I1 （Fv/Fm） was not altered by U. esculenta infection, indicating that U. esculenta infection may not be a biotic stress for Z. latifolia plants. Therefore, based on the changes of the plant growth indices, PS II efficiency and membrane peroxidation in infected plants, we found the interactive relationship between U. esculenta and Z. latifolia was neither pathogenic nor mutualistic.
出处
《生态学报》
CAS
CSCD
北大核心
2013年第5期1584-1593,共10页
Acta Ecologica Sinica
基金
国家公益性行业(农业)科研专项(200903017-03)
关键词
茭白
食用黑粉菌
抗氧化酶
超氧自由基
过氧化氢
丙二醛
叶绿素荧光
Zizania latifolia Turcz.
Ustilago esculenta
antioxidant enzymes
superoxide radical （O2＇-）
hydrogen peroxide （ H2O2 ）
malondialdehyde （MDA）
chlorophyll fluorescence
