Đang chuẩn bị liên kết để tải về tài liệu:
Báo cáo y học: "Floral induction and monocarpic versus polycarpic life histories"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Minireview cung cấp cho các bạn kiến thức về ngành y đề tài: Floral induction and monocarpic versus polycarpic life histories. | X Genome Biology Minireview Floral induction and monocarpic versus polycarpic life histories Richard Amasino Address Department of Biocemistry University of Wisconsin Babcock Drive Madison WI 53706-1544 USA. Email amasino@biochem.wisc.edu. Asbtract Recent work in Arabis alpina a perennial relative of Arabidopsis has uncovered subtle differences in control of a gene that represses flowering which contributes to the polycarpic habit. There are two extremes of life-history strategies in plants and animals - semelparity and iteroparity 1 . Semelparity is sometimes referred to as the big-bang reproductive strategy 2 as semelparous species devote most of their energy and resources to maximizing the number of offspring in a single cycle of reproduction and die soon after reproducing. Semelparity may be advantageous when the prospects for long-term survival are low. Iteroparous species in contrast reproduce multiple times a strategy that may be advantageous when prospects for long-term survival are good. In the plant kingdom there are extreme examples of both strategies. At one end of the iteroparous spectrum are redwood trees which can live for several thousand years with several thousand cycles of reproduction. In contrast the popular semelparous research model Arabidopsis thaliana can complete its life cycle in less than two months and once Arabidopsis produces a certain number of offspring it rapidly senesces and dies even under optimal growth conditions 3 Figure 1 . Plants that live and reproduce for many years such as redwoods are often referred to as perennials. Plants such as Arabidopsis that typically survive only a single growing season are often referred to as annuals. However the different life-history strategies of plants are better described by the terms monocarpic semelparous reproduces once and dies and polycarpic iteroparous reproduces repeatedly instead of annual and perennial respectively. For example perennial is hard to define because there are plants