Systemic accumulation of specific mRNAs in response to wounding in poplar trees.

Abstract

cDNAs for several transcripts that accumulate systemically in response to mechanical wounding in a hybrid poplar have been cloned. The corresponding mRNAs become abundant in the unwounded upper leaves of poplar trees whose lower leaves have been damaged. Two of the cDNA clones have been characterized by Northern and Southern blotting, and their nucleotide sequences have been determined. These clones, designated win6 (wound-inducible) and win8, are members of multigene families encoding proteins with a high degree of similarity to chitinases from bean, tobacco, and barley. This initial demonstration of a systemic response to wounding in trees provides an approach to study defense mechanisms in woody plants at the biochemical, physiological, and ecological levels.

Unexpected sequence similarity between nucleosidases and phosphoribosyltransferases of different specificity

“…Conceivably, dGTP phosphohydrolase and the new nucleosidase may be functionally linked. BSP-win4 family proteins in poplars are encoded by a family of physically linked genes and are induced by various stress signals, namely, elevated nitrogen level, short photoperiod, or mechanical wounding; BSP proteins serve as transient nitrogen deposit in bark (Parsons et al, 1989;Clausen & Apel. 1991;Coleman et al, 1992;Davis et al, 1993).…”

Rapid Activation of Phenylpropanoid Metabolism in Elicitor-Treated Hybrid Poplar (Populus trichocarpa Torr. & Gray × Populus deltoides Marsh) Suspension-Cultured Cells

“…Frozen tissue culture cells or leaf material was ground to a fine powder in liquid nitrogen; total RNA was extracted by the method of Parsons et al (26), and poly(A)+ RNA was isolated by oligo(dT)-cellulose affinity chromatography (29). RNA was separated on formaldehyde gels and blotted to Hybond (Amersham) membranes according to the manufacturer's specifications.…”

“…& Gray) and eastern cottonwood (Populus deltoides Marsh) have been developed for efficient production of fiber and fuel (17). In initial molecular studies of defense reactions in the P. trichocarpa x P. deltoides hybrid Hl -l1, it was shown that mRNAs encoding chitinases and other proteins accumulate systemically in plants subjected to severe wounding (26).…”

“…They are easily vegetatively propagated, have a small genome size (c value = 0.7 pg; ref. 26), and transformation by Agrobacterium tumefaciens and regeneration of transgenic trees are possible (8). Interspecific hybrids of North American western black cottonwood (Populus trichocarpa Torr.…”

Primary structure of chitosanase produced by Bacillus circulans MH-K1.

“…Studies about the reaction products of chitinase on partially N acetylated chitosan suggested the similarity of these enzymes (8,9). Some of the primary structures of chitinase genes have been reported (1)(2)(3)(4)(5)(6)(7)10,11,(13)(14)(15) Bacterial strains and growth conditions. Bacillus circulans MH-K 1 was used for preparation of chitosanase.…”