Research On Salt And Alkali Resistance In ClNAC9 Tansgenic Plants Of Chrysanthemum×Grandiflora

Chrysanthemum×grandiflora ’niu9717’ is a new species breeding form Chrysanthemum morifolium ’niu fenkou’ after boarding return satellite. Their advantages are low height plants, spend more dense, bright flower color and long flowering period. Transferring Exogenous Gene to improve the resistance of Chrysanthemum×grandiflora is of great significance to expand its application in landscape application. This paper mainly studies into transcriptome analysis and its tolerance to salt and alkali stress of Chrysanthemum×grandiflora ’niu9717’ transferred CINAC9 gene from Chrysanthemum lavandulifolium. The mainly research results are as follows1 By using high-throughput sequencing, analysis the transcriptome of Chrysanthem um×grandiflora ’niu9717’, obtained 91,182 unigene sequence from the mixed assembly of the transcription group data. Compared with transgenic lines(TL) and wild-type plant s(WT), in the significantly different expression of the 210 genes, T were 148 genes up-regulated, and 62 genes down-regulated of TL. Compared genes significantly difference expressed to the databases notes 91 genes, in which 22 genes were related to the resp onse to salt and alkali stress. It provide basis of the gene level to research that transfe rring CINAC9 gene enhanced its tolerance to salt and alkali stress of Chrysanthemum×g randiflora’niu9717’2 Under 200 mmol/L NaCl stress, the Chrysanthemum×grandiflora showed the following changes:With the extension of stress time, the plant morphology gradually appeared symptoms of stress, from the leaf yellowing to severe chlorosis and the plant wilting and death. The relative water content(RWC) show a downward trend. The relative electrical conductivity and MDA content presented rising trend, and the activity of SOD, POD and CAT showed the trend of first increased and then decreased, The two aspects of morphology and physiology showed that the resistance of three transgenic lines to 200mmol/L NaCl stress was significantly higher than that of wild type plants.3 The effect of different concentration salt solution to Chrysanthemum×grandiflora after 20 days with the concentration increasing showed the following rules:the plant morphology showed different changes, the greater the concentration, the more severe the symptoms of persecution. With increasing concentration, the WRC decreased continuously; The relative electrical conductivity and MDA content showed rising trend; changes of SOD, POD and CAT activity were different, But the enzyme activities of the three transgenic lines were significantly higher than that of the wild-type plants under the stress of each concentration. The experiment shows that the transgenic lines werw more resistant to high concentrations of salt stress than wild-type plants.4 100mmol/L NaHCO3 solution stress on Chrysanthemum×grandiflora showed a rule as follows:the plant morphology showed different changes, but the transgenic lines were less affected than the wild-type plants. The MDA content presented rising trend. Free proline content of three transgenic lines was more than that of wild type plants after 15 days of stress. Soluble protein content increased slightly first and then decreased. The activity of SOD, POD and CAT showed the trend of first increased and then decreased, but the highest value appeared at different time, and the activity of the three transgenic lines were significantly higher than that of wild type plants.5 The effects of alkali stress on Chrysanthemum×grandiflora after 15 days with the concentration increasing showed the rules as following:At the same concentration, the morphology of transgenic plants were damaged much less than that of wild-type plants. With increasing concentration, the MDA content showed rising trend. The content of free proline increased rapidly under 100mmol/L alkali stress. The soluble protein content of the transgenic lines was higher than that of the wild-type plants. The activity of SOD, POD and CAT showed the trend of first increasing and then decreasing, and the enzyme activities of the three transgenic lines were significantly higher than that of the wild-type plants.