Effects Of ABA、NDGA On Flowering Of Bougainvillea Glabra And The Isolation Cloning Of BgNCED Gene

Bougainvillea glabra Choisy as the Nyctaginaceae Bougainvillea Comm. Ex Juss. evergreen climbing shrub, alias Ye Zihua, Bao Jinghua, San Jiaomei, Jiu Chongge and so on. It is the important ornamental and excellent landscape plant of subtropical area. At the same time, Bougainvillea glabra is the city flower of Shenzhen, Xiamen, Huizhou City, Zhuhai, Sanya and Xichang City ect., widely cultivated in subtropical area. But the open field cultivation prone to excessive water does not blossom or does not concentrate phenomenon, serious impact on the landscape effect. At present the study on the regulation of flowering in Bougainvillea glabra mainly concentrated in the light, temperature, fertilizer and water management as well as B9, PP333, CCC ect. treatment. While, research by exogenous ABA and NDGA regulation of Bougainvillea flowering is very little, and on the mechanism of Bougainvillea flower hasn’t systematically study.Bougainvillea glabra was chosen as subjects and treated by different concentration of nordihydroguaiaretic acid(NDGA) and abscisic acid(ABA), and separation and cloning of BgNCED homologous gene is also studied simultaneously. The results show that:(1) External ABA can promote Bougainvillea flowers blossom and prolong the duration, in a certain range with the increase of ABA concentration, the effect is obvious. ABA=50mg/L, the flowering period is 5 days ahead of the CK, blossom lasts 64 days than the CK extension of 1 days; ABA=100mg/L, the flowering period is 11 days ahead of the CK, blossom lasts 67 days than the CK extension of 4 days; ABA=150mg/L, the flowering period is 10 days ahead of the CK, blossom lasts 69 days than the CK extension of 6 days, no significant difference of the 10.0mg/LABA.(2) The high concentration of NDGA (>10μmol/L) on Bougainvillea blossom has inhibitory effect, low concentration of NDGA (<10μmol/L) treatment and there was no significant difference between the ABA and NDGA control. NDGA=5μmol/L, the flowering period is 1 days ahead of the CK, blossom lasts 62 days than the CK by 1 days; NDGA=10μmol/L, the flowering period was delayed 2 days by the CK, blossom lasts 59 days than the CK by 4 days; NDGA=15μmol/L, the flowering period was delayed 6 days by the CK, blossom lasts 52 days than the CK by 11 days.(3) ABA and NDGA together treatment, Bougainvillea flower is influenced by the concentrations vary significantly, in a certain range of concentration both with application has a promoting effect on Bougainvillea blossom. the high concentration of ABA(≥ 100mg/L) with low concentration of NDGA (<10μmol/L) treatment to promote Bougainvillea flower has synergistic effect. ABA=100mg/L, NDGA=5μmol/L, the flowering period is 15 days ahead of the CK, blossom lasts 76 days than the CK extension of 13 days, and than 9 days of 100mg/LABA; ABA=150mg/L, NDGA=5μmol/L, the flowering period is 18 days ahead of the CK, blossom lasts 79 days than the CK extension of 16 days, and than 10 days of 150mg/LABA. While, the high concentration of NDGA (>10μmol/L) treatment decreased ABA blossom promotion effect to the Bougainvillea flower. All in all, spraying 150mg/L ABA and 5μmol/L NDGA ahead of the best blossom, blossom and the longest.(4) External ABA can obviously promote the plant endogenous ABA accumulation, and with the increase of external ABA concentration and the increase, but the effects of external ABA on endogenous ABA accumulation to promote the role of the existence of a limit value is not infinite, increases with the increasing concentration of external ABA; while NDGA(>10μmol/L) reduced the concentration of ABA, the interaction of NDGA with low concentration (<10μmol/L) and high concentration of ABA (≥100mg/L) instead of endogenous ABA content of plants increased with synergistic action.(5) Change trend of endogenous ABA and 9-cis-epoxycarotenoid dioxygenase(NCED) consistent content change tendency, first decreased and then slowly rising trend, indicates that NCED may be the rate limiting enzyme in the ABA biosynthetic pathway.(6) External ABA stimulated the enzymatic activity and concentration of ZEP, NCED and ZEP. It demonstrates that ABA can mediate its synthesis by autocatalystic reaction and single enzyme or single enzymatic reaction couldn’t reasonably explain the change of ABA level. It is concluded that ABA signal mechanism may be a result of coordination and system control by a multienzyme system.(7) According to the similar species NCED homologous gene conserved primers were designed, Bougainvillea glabra leaves as material, through PCR amplification, sequencing of the gene fragments of Blast ratio, NCBI, the results reported in this gene fragment and GenBank in Strawberry (Fragaria vesca) NCED1 gene homology of 91%, and European sweet cherry (Prunus avium) NCED1 homology 85%, and the grapes (Vitis vinifera) NCED1 homology 79%. It can be speculated that the gene fragment was cloned by BgNCED gene fragment as Bougainvillea glabra.