BIOSYNTHESIS & METABOLIC ENGINEERING OF OSMOPROTECTANTS IN PLANTS

总体目标是(A)确定生化防御 植物进化以帮助它们应对渗透的机制 应激，(B)定义和分离所涉及的酶，(C)克隆 相应的基因，以及(D)利用这些基因进行代谢 工程师提高了作物的抗逆性。我们的研究重点是 甜菜碱及其类似物，它们是有效的渗透保护剂 和冷冻保护剂。这些化合物及其生物合成 中间体非常容易进行质谱分析。特定的 目标是(I)利用克隆的植物基因来生产甘氨酸甜菜碱 合成以实现甜菜碱积累(由 USDA-NRI-CRGP)；(Ii)鉴定DMSP和 高等植物和海藻中的相关化合物，并分离 它们的酶和基因。

The overall goals are (a) to identify biochemical defense mechanisms that plants have evolved to help them cope with osmotic stress, (b) to define and isolate the enzymes involved, (c) to clone the corresponding genes, and (d) to use these genes to metabolically engineer improved crop stress resistance. Our research focuses on betaines and their sulfonium analogs, which are potent osmoprotectants and cryoprotectants. These compounds and their biosynthetic intermediates are highly amenable to mass spectral analysis. Specific objectives are (i) to use cloned plant genes for glycine betaine synthesis to engineer glycine betaine accumulation (supported by USDA-NRI-CRGP); (ii) to identify the biosynthetic pathways of DMSP and related compounds in higher plants and in marine algae, and to isolate their enzymes and genes.