Research on the action mechanisms of plant hormones

通过aba连接AEH Sepharose 4B亲和层析，从黄化绿豆幼苗中分离出可溶性脱落酸结合蛋白。它对ABA的解离常数为10^<-7> M.从黄化绿豆幼苗中也纯化出可溶性的赤霉素酸结合蛋白。利用胡萝卜组织克隆了生长素和脱落酸分别调控其合成的胚胎细胞蛋白AX 110和ECP 31。从黄瓜未成熟果实切片中纯化了生长素诱导的1-氨基环丙烷-1-羧酸（ACC）合成酶，并测定了部分氨基酸序列。利用确定的氨基酸序列合成的寡核苷酸，克隆了冬瓜生长素诱导的ACC合成酶cDNA，并确定了其序列。将RGS-28基因（水稻谷氨酰胺合成酶）5′侧2 kb片段与β -葡萄糖醛酸酶（GUS）报告基因融合，通过农杆菌介导转化导入烟草。启动子对外部施加的铵离子有反应。然而，外用GA的效果观察不明显。将萌发的水稻种子单独暴露于DNA去甲基化剂5-氮杂胞苷（aza C）或5-氮杂脱氧胞苷（aza dC）诱导矮化植株。从矮株植物中克隆了两个被这些药剂改变的基因组。利用玉米赤霉素响应突变体mays (d_5)，研究了赤霉素对玉米皮质微管（MT）取向的影响与生长矮化习性的关系。GA3处理24h后，刺激了d_5突变体中胚轴的生长，使玉米表皮细胞和皮层细胞的MTs取向变为横向。2-脱氧糖通过降低udp -糖的水平抑制细胞壁多糖的合成，从而抑制iaa诱导的黄瓜节段细胞伸长。聚焦结合凝集素抑制了生长素诱导的小豆上胚轴伸长。这些凝集素还能抑制生长素诱导的细胞壁片段松动。这些结果支持木葡聚糖的分解参与了生长素诱导的双子叶细胞壁松动的观点。少

A soluble abscisic acid-binding protein was isolated from etiolated mung bean seedlings by affinity chromatography on ABA-linked AEH Sepharose 4B. Its dissociation constant for ABA was 10^<-7> M. A soluble gibberelic acid-binding protein was also purified from etiolated mung bean seedlings.Embryogenic cell proteins (AX 110 and ECP 31) which synthesis were regulated by auxin and abscisic acid, respectively, were cloned using carrot tissues. 1-Aminocyclopropane-1-carboxylate (ACC) synthase induced by auxin was purified from slices of immature cucumber fruits, and partial amino acid sequences were determined. By using oligonucleotides synthesized based on the determined amino acid sequence, a cDNA for auxin-induced ACC synthase from winter squash was cloned and its sequence was determined.A 2-kb fragment from the 5'-flanking region of the RGS-28 gene (glutamine synthetase from rice) was fused to beta-glucuronidase (GUS) reporter gene and introduced into Nicotiana tabacum by Agrobacterium- … More mediated transformation. The promoter responded to externally applied ammonium ions. However, the effect of externally applied GA was not observed clearly.A single exposure of germinated rice seeds to either the DNA demethylating agents 5-azacytidine (aza C) or 5-azadeoxycytidine (aza dC) induced dwarf plants. Two genomes which were altered by these agents were cloned from dwarf plants.The relationship between the dwarf habit of growth and cortical microtubule (MT) orientation as affected by gibberellin was examined using a gibberellin responsive mutant of Zea mays (d_5). By GA3 treatment for 24h, the growth of d_5 mutant mesocotyls was stimulated, and the orientation of MTs in epidermal cells and cortex cells of Zea mays became transverse.2-Deoxysugars inhibit synthesis of cell-wall polysaccharides by decreasing the levels of UDP-sugars, thereby inhibiting IAA-induced elongation of cells in cucumber segments. Auxin-induced elongation of epicotyl segments of azuki bean was suppressed by fucose-binding lectins. These lectins also inhibited auxin-induced cell wall loosening of segments. These results support the view that the breakdown of xyloglucans is involved in the cell wall loosening responsible for auxin-induced elongation in dicotyledons. Less