title: Study on salt tolerance with YHem1 transgenic canola (Brassica napus).
abstract: 5-Aminolevulinic acid (5-ALA) has been suggested for improving plant salt tolerance via exogenous application. In this study, we used a transgenic canola (Brassica napus), which contained a constituted gene YHem1 and biosynthesized more 5-ALA, to study salt stress responses. In a long-term pot experiment, the transgenic plants produced higher yield under 200 mmol L(-1) NaCl treatment than the wild type (WT). In a short-term experiment, the YHem1 transformation accelerated endogenous 5-ALA metabolism, leading to more chlorophyll accumulation, higher diurnal photosynthetic rates and upregulated expression of the gene encoding Rubisco small subunit. Furthermore, the activities of antioxidant enzymes, including superoxide dismutase, guaiacol peroxidase, catalase and ascorbate peroxidase, were significantly higher in the transgenic plants than the WT, while the levels of O2 ·(-) and malondialdehyde were lower than the latter. Additionally, the Na(+) content was higher in the transgenic leaves than that in the WT under salinity, but K(+) and Cl(-) were significantly lower. The levels of N, P, Cu, and S in the transgenic plants were also significantly lower than those in the WT, but the Fe content was significantly improved. As the leaf Fe content was decreased by salinity, it was suggested that the stronger salt tolerance of the transgenic plants was related to the higher Fe acquisition. Lastly, YHem1 transformation improved the leaf proline content, but salinity decreased rather than increased it. The content of free amino acids and soluble sugars was similarly decreased as salinity increased, but it was higher in the transgenic plants than that in the WT.
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xin-E
authors.initials: XE
authors.lastname: Sun
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xin-Xin
authors.initials: XX
authors.lastname: Feng
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Cui
authors.initials: C
authors.lastname: Li
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Zhi-Ping
authors.initials: ZP
authors.lastname: Zhang
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Liang-Ju
authors.initials: LJ
authors.lastname: Wang
mesh_terms: D000622:Aminolevulinic Acid / Q000378:metabolism*; D060387:Ascorbate Peroxidases / Q000378:metabolism; D029688:Brassica napus / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D002374:Catalase / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D010788:Photosynthesis / Q000502:physiology; D018515:Plant Leaves; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011392:Proline / Q000378:metabolism; D054712:Salinity; D055049:Salt Tolerance; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D002734:Chlorophyll; D012965:Sodium Chloride; D000622:Aminolevulinic Acid; D011392:Proline; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase