Improvement of petal pigmentation and flowering, and regulation of senescence in cut flowers through introducing fructan synthesis genes

(1)研究了弱光对桔梗花瓣色素沉着的影响。整株或茎叶部分遮荫显著降低了花瓣颜色强度，而花的遮荫对花瓣颜色强度没有影响。将带花梗的离体花置于蔗糖溶液中，随着蔗糖浓度的增加，花瓣颜色变得更加强烈，查尔酮合成酶、查尔酮异构酶和二氢黄酮醇4-还原酶转录物的水平也随之增加。这些结果表明，在低光强下，光合产物供应减少是导致花瓣颜色苍白的原因。(2)在含0.05 mg/l IBA、1 mg/l BA和0.1 mg/l GA3的MS培养基上，叶片每培养可产生8 ~ 18个芽。幼苗在含IAA的MS培养基上孵育后，置于含IBA的1/2强度MS培养基上。他们在40到50天内扎根。(3)利用pB121和农杆菌LBA4404分别将大麦中的6-蔗糖-果聚糖基转移酶（6-SFT）基因和枯草芽孢杆菌中的SacB基因导入到百合中。将SacB基因融合到甘薯孢子素液泡靶向序列中。通过卡那霉素抗性和PCR分析筛选转化子。我们无法获得6-SFT的任何转化，而SacB基因的32个外植体对卡那霉素具有抗性，根据PCR分析，15个卡那霉素抗性植株中100%含有SacB基因。(4)转化植株生根和后续生长较差，未达到开花期。在评价引入果聚糖合成基因对花色素的影响之前，需要对生根后的培养条件和驯化条件进行复核。

(1) We investigated the influence of low light intensity on petal pigmentation in lisianthus. Shading whole plants or the stem and leaf parts significantly reduced the intensity of petal color, whereas shading flowers had no effects on it. When detached flowers with peduncles were placed in sucrose solutions, their petal color became more intense as the sucrose concentration increased, concomitantly with increased levels of chalcone synthase, chalcone isomerase, and dihydroflavonol 4-reductase transcripts. These results suggest that reduced supply of photosynthates is responsible for pale petal color under low light intensity.(2) Leaf section produced 8 to 18 shoots per culture on MS media containing 0.05 mg/l IBA, 1 mg/l BA, and 0.1 mg/l GA3. These shoots were placed on 1/2 strength MS media containing IBA after they were incubated on MS media containing IAA.They rooted within 40 to 50 days.(3) We attempted to introduce 6-sucrose : fructan fructosyltransferase (6-SFT) gene from barley and SacB gene from Bacilus subtilis into lisianthus plants using pB121 and Agrobacterium tumefacience LBA4404. SacB gene was fused to vacuolar targeting sequence of sweet potato sporamin. The transformants were screened by kanamycin resistance and PCR analysis. We could not obtain any transformats for 6-SFT However, for SacB gene, 32 explants were kanamycin resistant and 100 % out of 15 kanamycin-resistant plants contained SacB gene according to PCR analysis.(4) The rooting and subsequent growth of the transformants were poor, and they did not reach the flowering stage. Reexamination of culture condition after rooting and acclimation condition will be needed before evaluating the effect of introducing fructan synthesis genes on flower pigmentaion.