| The damage mechanism of salt stress on plant has been widely reported, but the ornamental plants seldom reported. Lily is salt-sensitive flowers and physiological research of lily is confined to the high temperature stress and the physiology of flower preservation. Therefore, the study of lily salt stress response and salt tolerance in theory and applications are of great significance. In this study, by Lilium longiflorum tissue culture materials, on the one hand, membrane permeability, proline content, antioxidant enzyme activity and the content of antioxidants are measured indicators. They explore the dynamic changes as the salt and salt stress evaluation of the feasibility. On the other hand, the transgenic research of lily was done for obtaining transgenic (S6PDH) resistant plants to supply scientific theory for studying the mechanism of salt-resistant and the cultivation of salt-resistant fine. The main findings are as follows :(1) Physiological effects of NaCl on salt stress of lily plantlets from tissue cultureBy experiment , the threshold about salt tolerance of lily microplants is 8 g.L-1 NaCl. The results showed that the content of Malondialdehyde (MDA) and the leakage of electrolytes increased when treated with 8 g.L-1 NaCl, and the changes in leaves were more obvious than that in roots. Proline (Pro) content did not show a obvious regulation. The activities of antioxidant enzymes (SOD, POD, CAT and APX) increased under first period of salt stress and then increased. The change was more obvious in leaves than in roots. Meanwhile, the content of ASA was decreased and it changed more rapidly in leaves than in roots. It is concluded that the roots of lily had better salt tolerance than the leaves. MDA and the leakage of electrolytes could be used as stable indicators of the salt tolerance evaluation and Pro is not appropriate.(2) Transformed lilium with S6PDH gene had been obtainedA. With vitro leaves of Lilium longiflorum as the receptor materials, S6PDH gene was transformed to lily by Agrobacterium tumefaciens-mediated method. Through the study on the efficiency of Agrobacterium mediated genetic transformation of lily, the several major factors are explored. The major factors affecting are as follows : Lily leaf had been pre-cultured for 3 days ,appropriate concentration of Agrobacterium infection was OD600 0.6, infection time 10min, co-cultured on the culture medium in the dark for 3 days, which could increase the conversion rate of Lily. The sensitivity of lily's leaf explant to kan, was used to 50 mg.L-1.B. 40 Kanamycin resistant seedlings were achieved, 6 Kanamycin resistant seedlings were at random selected for PCR and got the strip. S6PDH activity of lily under 10 g.L-1 NaCl stress for 3d had been measured, showed 57.34 umol NADPH g-1FWh-1 for strain 7 and 11.50 umol NADPH g-1FWh-1 for strain 9. It proved preliminarily that foreign gene had been integrated into lily genome.(3) Salt-resistant identification on transformed plant of lilium with S6PDH GeneThe six resistant plants by PCR detection were related to the determination of the physiological indicators, found that only strain 7 showed significant resistant law :With salt stress (10 g.L-1 NaCl) to extend the time, conductivity and MDA content of Leaves of strain 7 lines and the control (non-transformed seedlings) showed an upward trend, and soluble protein content decreased, while SOD, POD, CAT, APX activity showed first rose, then fell down. But in the all process of salt stress, conductivity and MDA content of transformed plant were less, and soluble protein content higher than that of the control. Moreover transformed plant had higher activities than no-transformed plant. Transformed plant had clearly demonstrated a strong salt tolerance. |
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