光合菌对黄瓜光合及抗氧化同工酶的影响

Effects of Photosynthetic Bacteria on Photosynthesis and Antioxidative Isoenzymes in Cucumber (Cucumis sativus)

以2种基因型的黄瓜(Cucumis sativus)为材料,研究光合菌(PSB)的喷施对植物生物量、净光合速率(Pn)、叶片PSII的最大光化学效率(Fv/Fm)及抗氧化同工酶代谢的影响。结果表明,喷施PSB均能诱导2种基因型黄瓜的生物量显著增加,并伴随Pn的显著提高。但是,2种基因型黄瓜的Fv/Fm并不受PSB喷施的影响;PSB能使总过氧化物歧化酶(SOD)和抗坏血酸过氧化酶(APX)活性提高,并使它们的多数同工酶的活性上调,这些同工酶活性的增加在叶绿体中表现更为明显(如Cu/Zn-SOD、Fe-SOD和sAPX)。研究结果表明,PSB能通过增强黄瓜抗氧化酶体系的活性改善植株的抗氧化能力,从而在植株的生长和光合作用方面起到促进作用。

We examined the net photosynthetic rate （Pn）, the maximal photochemical efficiency of PSII （Fv/Fm） and the activities of antioxidant isoenzymes in cucumber （Cucumis sativus） with or without photosynthetic bacteria （PSB） application. PSB spraying resulted in a significant increase in fresh weight and leaf area for both genotypes of cucumber plants, accompanied by a marked increase of Pn. However, Fv/Fm showed negligible changes. Exogenous PSB also increased activities of total superoxide dismutase （SOD） and ascorbate peroxidase （APX）, and a general increase of their isoenzymes. The increased level in Cu/Zn-SOD, Fe-SOD and stroma APX （sAPX） was most significant in chloroplasts. These results implied that PSB played a favorable role in growth and photosynthesis and improved hardiness in cucumber by enhancing antioxidant enzyme activities.