Plant Biology Laboratory, Salk Institute for Biological Studies, PO Box 85800, San Diego, CA 92138, USA.
EMBO J. 1987 Jun;6(6):1527-33. doi: 10.1002/j.1460-2075.1987.tb02396.x.
The environmentally regulated synthesis of phenylpropanoid natural products was studied by examining the expression of the gene encoding chalcone isomerase (CHI). This enzyme catalyzes a step common to the synthesis of flavonoid pigments and isoflavonoid phytoalexins. A lambdagt11 library was constructed using mRNA from cell cultures of bean (Phaseolus vulgaris L.) treated with fungal elicitor. Two positive clones were obtained by screening 10 recombinants with an antiserum to purified bean CHI. The identity of the cloned sequences was confirmed by hybrid-select translation and the production of antigenic polypeptides from transcripts synthesized in vitro. Addition of elicitor to cell cultures resulted in the rapid accumulation of CHI mRNA, with maximum levels achieved 3-4 h after elicitation. CHI mRNA also accumulated during the natural infection of hypocotyls with the fungal pathogen Colletotrichum lindemuthianum, and in mechanically wounded hypocotyls. The kinetics of accumulation of CHI mRNA in response to these environmental signals were strikingly similar to those of mRNAs encoding two other phenylpropanoid pathway enzymes, phenylalanine ammonialyase and chalcone synthase. In contrast to the multi-gene families encoding these two enzymes, chalcone isomerase is encoded by a single gene which is regulated by several environmental stimuli.
环境调控的苯丙烷类天然产物合成研究，通过检查基因编码查尔酮异构酶（CHI）的表达来进行。该酶催化黄酮类色素和异黄酮植物抗毒素合成的共同步骤。利用真菌诱导子处理的菜豆（Phaseolus vulgaris L.）细胞培养物的 mRNA 构建了一个 lambdagt11 文库。用纯化的菜豆 CHI 抗血清筛选 10 个重组体，获得了 2 个阳性克隆。通过杂交选择翻译和体外合成的转录物产生抗原性多肽，证实了克隆序列的同一性。添加诱导子到细胞培养物中导致 CHI mRNA 的快速积累，最大水平在诱导后 3-4 小时达到。CHI mRNA 在菜豆下胚轴与真菌病原体炭疽菌的自然感染过程中以及在机械损伤的下胚轴中也会积累。CHI mRNA 对这些环境信号的积累动力学与编码另两种苯丙烷途径酶（苯丙氨酸氨裂解酶和查尔酮合酶）的 mRNA 的积累动力学非常相似。与编码这两种酶的多基因家族不同，查尔酮异构酶由一个基因编码，该基因受多种环境刺激调控。
