title: Growth, photosynthesis and antioxidant responses of endophyte infected and non-infected rice under lead stress conditions.
abstract: An endophytic fungus was tested in rice (Oryza sativa L.) exposed to four levels of lead (Pb) stress (0, 50, 100 and 200 μM) to assess effects on plant growth, photosynthesis and antioxidant enzyme activity. Under Pb stress conditions, endophyte-infected seedlings had greater shoot length but lower root length compared to non-infected controls, and endophyte-infected seedlings had greater dry weight in the 50 and 100 μM Pb treatments. Under Pb stress conditions, chlorophyll and carotenoid levels were significantly higher in the endophyte-infected seedlings. Net photosynthetic rate, transpiration rate and water use efficiency were significantly higher in endophyte-infected seedlings in the 50 and 100 μM Pb treatments. In addition, chlorophyll fluorescence parameters Fv/Fm and Fv/Fo were higher in the infected seedlings compared to the non-infected seedlings under Pb stress. Malondialdehyde accumulation was induced by Pb stress, and it was present in higher concentration in non-infected seedlings under higher concentrations of Pb (100 and 200 μM). Antioxidant activity was either higher or unchanged in the infected seedlings due to responses to the different Pb concentrations. These results suggest that the endophytic fungus improved rice growth under moderate Pb levels by enhancing photosynthesis and antioxidant activity relative to non-infected rice.
authors.affiliation: College of Chemistry and Life Science, Shenyang Normal University, Shenyang 110034, PR China. lxmls132@163.com
authors.forename: Xuemei
authors.initials: X
authors.lastname: Li
authors.forename: Ning
authors.initials: N
authors.lastname: Bu
authors.forename: Yueying
authors.initials: Y
authors.lastname: Li
authors.forename: Lianju
authors.initials: L
authors.lastname: Ma
authors.forename: Shigang
authors.initials: S
authors.lastname: Xin
authors.forename: Lihong
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D018533:Biomass; D002338:Carotenoids / Q000096:biosynthesis; D019663:Chenopodiaceae / Q000378:metabolism; D002734:Chlorophyll / Q000096:biosynthesis; D003470:Culture Media; D060026:Endophytes / Q000378:metabolism*; D007854:Lead / Q000633:toxicity*; D008315:Malondialdehyde / Q000378:metabolism; D009566:Nitrates / Q000633:toxicity*; D012275:Oryza / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D010788:Photosynthesis / Q000187:drug effects*; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D013050:Spectrometry, Fluorescence
chemical_list: D000975:Antioxidants; D003470:Culture Media; D009566:Nitrates; D002734:Chlorophyll; D007854:Lead; D002338:Carotenoids; D008315:Malondialdehyde; C017461:lead nitrate