Identification of a Receptor Protein in Cotton Fibers for the Herbicide 2,6-Dichlorobenzonitrile

摘要: The herbicide 2,6-dichlorobenzonitrile (DCB) is an effective and apparently specific inhibitor of cellulose synthesis in higher plants. We have synthesized a photoreactive analog DCB (2,6-dichlorophenylazide [DCPA]) for use as affinity-labeling probe to identify the receptor This retains activity inhibits cotton fibers tobacco cells manner similar DCB. When fiber extracts are incubated with [3H]DCPA exposed ultraviolet light, 18 kilodalton polypeptide specifically labeled. About 90% this found 100,000g supernatant, remainder being membrane-associated. Gel filtration nondenaturing polyacrylamide gel electrophoresis indicate that it acidic protein which has size its native or denatured state. amount detectable by [3H]DCPA-labeling increases substantially at onset secondary wall fibers. A polypeptide, but lower molecular weight (12,000), been detected upon labeling from tomato cellulosic alga Chara corallina. specificity coupled pattern developmental regulation, implicate role biosynthesis. Being, most, only loosely associated membranes, unlikely be catalytic synthase, we suggest instead may function regulatory β-glucan