在拟南芥中，花序分生组织的伸长而非花原基的形成受到光周期的调控。

Inflorescence shoot elongation, but not flower primordia formation, is photoperiodically regulated in Arabidopsis lyrata.

机构信息

Department of Ecology and Genetics, University of Oulu, FIN-90014 Oulu, Finland.

Max Planck Institute for Plant Breeding Research, Carl von Linné Weg, Cologne, Germany.

出版信息

Ann Bot. 2019 Aug 2;124(1):91-102. doi: 10.1093/aob/mcz035.

DOI:10.1093/aob/mcz035

PMID:31321402

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6676387/

Abstract

BACKGROUND AND AIMS

Photoperiod contains information about the progress of seasons. Plants use the changing photoperiod as a cue for the correct timing of important life history events, including flowering. Here the effect of photoperiod on flowering in four Arabidopsis lyrata populations originating from different latitudes was studied, as well as expression levels of candidate genes for governing the between-population differences.

METHODS

Flowering of plants from four A. lyrata populations was studied in three different photoperiods after vernalization. Flowering development was separated into three steps: flower primordia formation, inflorescence shoot elongation and opening of the first flower. Circadian expression rhythms of the A. lyrata homologues of GIGANTEA (GI), FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 (FKF1), CONSTANS (CO) and FLOWERING LOCUS T (FT) were studied in three of the populations in the intermediate (14 h) photoperiod treatment.

KEY RESULTS

Most plants in all populations formed visible flower primordia during vernalization. Further inflorescence development after vernalization was strongly inhibited by short days in the northern European population (latitude 61°N), only slightly in the central European population (49°N) and not at all in the North American populations (36°N and 42°N). In the 14 h daylength, where all plants from the three southernmost populations but only 60 % of the northernmost population flowered, the circadian expression rhythm of the A. lyrata FT was only detected in the southern populations, suggesting differentiation in the critical daylength for activation of the long-day pathway. However, circadian expression rhythms of A. lyrata GI, FKF1 and CO were similar between populations.

CONCLUSIONS

The results indicate that in A. lyrata, transition to flowering can occur through pathways independent of long days, but elongation of inflorescences is photoperiodically regulated.

摘要

背景和目的

光周期包含季节进展的信息。植物将不断变化的光周期作为 cues，用于正确安排包括开花在内的重要生活史事件的时间。本研究探讨了来自不同纬度的四个拟南芥 lyrata 种群对开花的光周期反应，以及调控种群间差异的候选基因的表达水平。

方法

在春化后，将四个 A. lyrata 种群的植物置于三种不同的光周期下进行开花研究。将开花发育分为三个步骤：花原基形成、花序伸长和第一朵花开放。在三种中间（14 小时）光周期处理中，研究了三个种群中 A. lyrata 同源物 GI、FLAVIN-BINDING、KELCH REPEAT、F-BOX 1（FKF1）、CONSTANS（CO）和 FLOWERING LOCUS T（FT）的昼夜节律表达节律。

结果

在所有种群中，大多数植物在春化过程中形成可见的花原基。在北欧种群（纬度 61°N）中，短日照强烈抑制了春化后的花序进一步发育，而在中欧种群（49°N）中则受到轻微抑制，在北美种群（36°N 和 42°N）中则完全不受抑制。在 14 小时的日长下，来自三个最南端种群的所有植物都开花，但只有最北端种群的 60%开花，在南部种群中检测到 A. lyrata FT 的昼夜节律表达节律，表明在激活长日途径的临界日长上存在分化。然而，A. lyrata GI、FKF1 和 CO 的昼夜节律表达节律在种群间相似。