摘要
为了解析转PEPC基因水稻的光保护机制,比较了转磷酸烯醇式丙酮羧化酶基因水稻(PEPC基因)和未转基因原种(WT)在夏季晴天10 :0 0时和14 :0 0时(光强最强,气温最高)的净光合速率(Pn)、原初光化学效率Fv Fm 、超氧阴离子(O- ·2 )的产生速率以及膜脂过氧化物丙二醛(MDA)的变化,着重研究了自然条件(连体叶片)、人工光氧化(叶圆片浸于蒸馏水)、经外源甲基紫精(MV)处理的连体叶片和叶圆片浸于5mmol LMV溶液中,超氧化物歧化酶(SOD)和过氧化物酶(POD)的日变化。结果表明,与原种WT相比,转PEPC基因水稻,随光氧化逆境的加剧,SOD和POD诱导活性逐步增强,O- ·2 的产生速率较低,MDA积累较少,维持较稳定的PSⅡ活性和光合能力,表现耐光抑制(光氧化)。可见,与原种相比,转PEPC基因水稻的光氧化耐性与其叶内较高的SOD和POD活性,较稳定的光合速率,PSⅡ活性以及较低的O- ·2 和MDA积累密切相关。
To elucidate the mechanism of photoprotection in PEPC transgenic plant, net photosynthetic rate(P n), PSⅡ primarily chemical efficiency (F v/F m),endogenous superoxide anion generation rate(O -· 2), the malondialdehyde (MDA) content between 10:00 am and 14:00 pm and diurnal variation in activities of superoxide dismutase (SOD) and peroxidase (POD) in leaves response to natural light, in the presence and absence of 5 mmol/L methyl viologen were compared between PEPC transgenic plant and untransformed rice plant(WT). The results showed that relative to untransformed rice, PEPC transgenic plant exhibited higher photooxidation induced activities of SOD and POD gradually, which led to a less generation rate of O -· 2 and MDA accumulation. Correspondingly, PEPC transgenic plants revealed a higher level of F v/F m and net photosynthetic rate, which showed a stronger tolerance to photoinhibition (photooxidation). It is suggested that the photooxidation tolerance of PEPC transgenic rice is related with the higher antioxidant enzymes( SOD and POD )activities and lower levels of O -· 2, and MDA and more stable PSⅡ activity than those of WT.
出处
《作物学报》
CAS
CSCD
北大核心
2005年第4期408-413,共6页
Acta Agronomica Sinica
基金
江苏省自然科学基金项目 (BK2 0 0 44 2 9)
江苏省农业科学院基金项目 (6110 419)
国际科技合作重点项目 (2 0 0 2AA2 1714 1)
