Plant Abiotic Stress Research And New Varieties Of Phalaenopsis Cultivation

The relative quantity of two kinds of fatty acids including unsaturated and saturated fatty acids of membrane lipids are very important for plants to cope with the cold-stress, for the reason that it can regulate the fluidity of membrane. We cloned the 5'-region of gene OsFAD8, called OsFAD8P. It is the first time for the work of cold-induced promoter in Oryza sativa L.We investigated the expression of GUS which was promoted by this promoter on different situation and the expression trend of GUS quantity go with the change of the temperature. We cloned the cold-inducible genetic constructs:OsFAD8P-GUS, and conducted the genetic transformation on the herbage and woody plants by Agrobacterium-mediated transformation method. In transgenic callus tissue of rice and seedings of Arabidopsis thaliana, the promoter OsFAD8P promoted the expression of the down-stream gene when exposured to cold, and the quantity of GUS was more expressed as the temperature decreased and time prolonged. GUS was hardly detected in the pod, but it was observed after the seed of Arabidopsis thaliana germinated 5 days later and also in 7 days old seeding of the Arabidopsis thaliana. While it was abundantly expressed in the nervation of the leaves, stem near the inflorescence and base of the root. Little expression was detected in the mesophyll. And the promoter also sensitive to other abiotic-stress as well as hormone like ABA,6-BA, and the growth and development of the transgenic plants are normal as the WT. Rchspl7.8 cloned from Chinese rose is belongs to a cytosolic class I sHSP, and it is induced under different stress. In order to study the physiological function of Rchspl7.8, we subcloned the ORF of Rchsp17.8 recombined after 35S:promoter into DH5α, then transformed into plant gene expression vector Agrobaterium rumefaciens, Leaf disc of tobacco was infected by Agrobaterium and three transformants were attained. We assessed the phenotype, relative electrical leakage, proline content, water lose rate under high temperature, osmotic stress, and salt stress respectively, and the transcript levels of P5CS gene was also investigated by semi-quantitative RT-PCR Results showed that transgenic line showed lower relative electrical leakage, more proline content, lower water lose rate, and the expressed of P5CS was elevated. Compared with the non-transgenic lines, transformed ones showed obvious resistance to high temperature and osmotic stress. The possible mechanism to different abiotic stress was also discussed. The economic value of flowers are much more larger than before. So how to change the quality of them, it seems quite important. Quality of flowers is including: shape of flowers, the size of flowers, the color of flowers, the flowers fragrance, and the florescence time. And especially the color and the florescence time are appreciated by people. And Phalaenopsis are much more popular in the society as ornamental than before. In order to increase the commercial value of the Phalaenopsis, people pay much more attention to improve the quality of them from the aspects of color and time of flowering. We try to change the color of Phalaenopsis by transfer the gene PhCHS5 and PhFS'5'H, so as to obtain the new species of Phalaenopsis and improve the commercial value of the Phalaenopsis, at the same time, the co-transformation is a n ew try for the breeding in this study and it can be a further study for the gene regulation of Phalaenopsis.