Over-expression Of Atchyb Affect The Resistance To Oxidation Of Transgenic Eustoma Grandiflorum

Eustoma grandiflorum Shinn is a famous ornamental flowers and is very popularin the cut flower market. The transgenic Eustoma withβ-carotene hydroxylase(AtchyB) gene is used in this experiment. AtchyB is cloned from Arabidopsis thalianaencoding β-carotene hydroxylase (BCH), a key enzyme in the carotenoids metabolicpathway.The transgenic lines were detected by PCR、 RT-PCR and Northern blottechnology. Transgenic lines-L8, L25-were confirmed to be the positive plants. UV-Bradiation was applied to the transgenic lines (L8, L25) and wild line (WT), whichwere taken as the experimental group. The same lines without radiation were taken asthe control group. Then the carotenoids content, oxydase activities （SOD、POD、CAT）, MDA content and the photosynthetic parameters between the control andexperimental groups were analyzed.The results were as follows:1）The expression of AthcyB gene was strengthenedin the transgenic lines, especially in the experimental group. The carotenoids relatedto the oxidation resistance in the transgenic lines were much higher compared to WT.Besides, the xanthophyll cycle was strongly enhanced in transgenic lines.2) Thenon-enzymatic system had an effect on the enzymatic system, so there were somedifferences in the oxydase activities between the transgenic lines and WT. Theactivities of SOD in the transgenic lines were more sensitive to the UV-B radiationstress, but there was no significant difference in MDA content probably due to thesynergy of the two systems.3) The Fv/Fm and PSII value of transgenic lines werehigher, which showed the stronger photosynthetic efficiency under the UV-Bradiation. The undifferentiated qP showed no effect on the photochemical quenching.For the higher content of NPQ in L25, its non-photochemical quenching ability wasimproved.Over-expression of AtchyB affected the biosynthetic pathway of carotenoids,which made the flower colour change to bright yellow in the later of the floweringtime. We found that the plants had sowed in March had a longer flowering time,because the temperature was optimal to the growth of the plants. The plant height,stem diameter, number of buds and flowers had no significant difference between WT and the transgenic lines. But some transgenic plants had specific properties. Some ofthe stems were especially short and thick. This was probably because the integrationof the exogenous gene affected the genome of the plants.