Cloning And Analysis Of Genes Releated To Floral Development In Narcissus Tazetta Var. Chinensis

Narcissus tazetta var. chinensis is a kind of herbaceousperennid, and belongs to the familyAmaryllidaceae. As one of ten Chinese traditional flowers, city flower in Zhangzhou andprovincial flower in Fujian Province, it has long cultivating history in China. At present, thereare cultivars with simple and double flowers. In order to illustrate the molecular mechanism offloral development, the research used 'Jinzhanyintai' as experimental materials, cloned theMADS-box genes, which may display adjusting function on its floral development, andanalyzed the expressions in different tissues and organs from simple and double flowers. Theseresults provided a reference for improving and innovating new species of Narcissus tazetta var.chinensis, enriched the molecular model of floral development, provided the complement to theresearch of floral development in monocotyledon. The main research findings are described asfollowings:1. A gene named as NtAP1gene (JN704304) was cloned from the flower bud of'jinzhanyintai' by RT-PCR and RACE methods. The cDNA was1155bp in length with an openreading frame762bp which was capable of encoding253amino acids. Phylogenetic treeanalysis indicated that the gene belonged to the APl/AGL9family AP1clade. Thetissue-specific expression pattern was studied by RT-PCR method. The expression resultsshowed that it expressed at every flower parts, and the highest at pistil. This showed that theNtAP1gene which cloned in this study did not play an important role in the formation processof double flowers of Narcissus tazetta var. chinensis.2. A gene named as NtPI (JQ326272) which belonged to the AP3/PI family PI lineage wascloned from the flower bud of 'jinzhanyintai'. The cDNA was897bp in length with an openreading frame619bp which was capable of encoding205amino acids. RT-PCR revealed thatthe esistence of NtPI was detectable in flowers, while the levels were much higher in stamenand pistil than in petal and corana from 'Jinzhanyintai', but the levels were much higher in petaland corana than in stamen and pistil from 'Yulinglong'.Thus, the gene plaied an important rolein the formation process of 'Yulinglong'.3. D–function gene NtSEEDSTICK was cloned from the flower bud of 'jinzhanyintai'. ThecDNA was884bp in length with an open reading frame705bp which was capable of encoding234amino acids. RT-PCR revealed that the expression of SEEDSTICK-like was detectable inpistil and ovary from simple and double flowers. This showed that the gene did not participatein the formation of double flowers.4. A gene named as NtAGL6gene which belonged to the AGL6family was cloned from theflower bud of 'jinzhanyintai'. The cDNA was1019bp in length with an open reading frame723 bp which was capable of encoding240amino acids. RT-PCR revealed that the expression ofAGL6-like was detectable in petal and stamen from 'Jinzhanyintai', while it existed in thewhole flower from 'Yulinglong'.