跳至主要内容

Stress-Induced Flowering in Pharbitis

Flowering in many plant species is usually regulated by environmental cues, such as night length in photoperiodic flowering and temperature in vernalization. However, some studies have indicated that stress is also a cue to induce flowering. In fact, plants flower as an emergency response when stressed, ensuring their ability to produce the next generation. Through this mechanism, the species is preserved, even under unfavorable environmental conditions. Therefore, stress-induced flowering is universal and as important as photoperiodic flowering and vernalization.

In this article, physiological characteristics, the regulation by salicylic acid (SA) and the expression of flowering-related genes in stress-induced flowering in pharbitis were reviewed. Pharbitis flowered under long-days in response to poor nutrition or low temperature. The pharbitis plants induced to flower by stress reached anthesis, fruited and produced fertile seeds. The progeny of the stressed plants developed normally. Grafting experiments indicated that a transmissible flowering stimulus was involved in poor nutrition stress-induced flowering. Aminooxyacetic acid (AOA), a phenylalanine ammonia-lyase (PAL) inhibitor, inhibited the stress-induced flowering, and this inhibition was overcome by SA. Stress induced PAL activity and SA biosynthesis. PnFT2, a pharbitis ortholog of the flowering gene FLOWERING LOCUS T of Arabidopsis thaliana, was expressed when the plants were induced to flower by stress. The overexpression of PnFT2 induced flowering, and PnFT2RNAi inhibited it. AOA inhibited PnFT2 expression induced by stress, and SA eliminated this inhibitory effect. SA enhanced PnFT2 expression under poor nutrition, but not under non-stressful conditions. Therefore, stress may induce the production of SA and other unknown factor(s) that may work in combination to induce PnFT2 expression and flowering.

In conclusion, pharbitis is typically induced to flower under short-day (SD) conditions and can be induced to flower under unfavorable photoperiodic conditions when exposed to stress. And stress activates PAL and enhances SA levels, promoting PnFT2 expression to induce flowering. However, SA alone cannot induce flowering, and other factors are necessary.

Article by Kaede C. Wada, et al, from Niigata University, Niigata, Japan.

Full access: http://mrw.so/1SYZ8S
Image by myu-myu, from Flickr-cc.

评论

发表评论

此博客中的热门博文

Identifying Sustainable Practices for Tapping and Sap Collection from Birch Trees

Tapping and collecting sap from birch trees ( Betula , sp.) for the production of beverages and syrup is gaining increased levels of interest. Although the practice of tapping birch trees and collecting sap has been ongoing for millennia across the world, there remain some critical data needed in order to make science-based decisions about the production practices required to optimize yields and ensure sustainable outcomes are achieved in the long-term. In this study, experiments were conducted to determine two pieces of information essential to identify practices necessary to ensure tapping trees for birch sap collection were both sustainable and profitable—the selection of the time to initiate tapping birch trees to obtain maximum yields, and the volume of nonconductive wood (NCW) associated with taphole wounds in birch trees. The yields obtained from various timing treatments varied between sapflow seasons, but indicated that using test tapholes to choose the appropriate ti
发表评论
阅读全文

Incorporation of High-Altitude Balloon Experiment in High School Science Classrooms

High-altitude balloon is a balloon, filled usually with helium or hydrogen that ascends into an area called “near space” or stratosphere. The most common type of high-altitude balloons are weather balloons. Other purposes include use as a platform for experiments in the upper atmosphere. Modern balloons generally contain electronic equipment such as radio transmitters, cameras, or satellite navigation systems, such as GPS receivers. The mission of the High-Altitude Balloon Experiment (HABE) is to acquire supporting data, validate enabling technologies, and resolve critical acquisition, tracking, and pointing (ATP) and fire control issues in support of future space-based precision pointing experiments. The use of high-altitude balloons offers a relatively low-cost, low-vibration test platform, a recoverable and reusable payload, worldwide launch capability, and a 'near- space' emulation of the future space systems operational scenarios. More recently, several university
1 条评论
阅读全文

Esophageal Carcinogenesis

Read full paper at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=50380#.VDy9v1fHRK0 Author(s)   Naoki Watanabe 1 , Masahito Shimizu 2 , Takahiro Kochi 2 , Yohei Shirakami 2 , Takuji Tanaka 1,3* Affiliation(s) 1 Department of Diagnostic Pathology (DDP) & Research Center of Diagnostic Pathology (RC-DiP), Gifu Municipal Hospital, Gifu, Japan . 2 Department of Internal Medicine/Gastroenterology, Gifu University Graduate School of Medicine, Gifu, Japan . 3 Department of Tumor Pathology, Gifu University Graduate School of Medicine, Gifu, Japan . ABSTRACT Esophageal cancer is the sixth leading cause of cancer death and remains one of the least survivable cancers. Esophageal cancers show wide variations in incidence in different pop
发表评论
阅读全文