Data from: Fluctuating, warm temperatures decrease the effect of a key floral repressor on flowering time in Arabidopsis thaliana

The genetic basis of growth and development is often studied in constant laboratory environments; however, the environmental conditions that organisms experience in nature are often much more dynamic. We examined how daily temperature fluctuations, average temperature, day length and vernalization influence the flowering time of 59 genotypes of Arabidopsis thaliana with allelic perturbations known to affect flowering time. For a subset of genotypes, we also assessed treatment effects on morphology and growth. We identified 17 genotypes, many of which have high levels of the floral repressor FLOWERING LOCUS C (FLC), that bolted dramatically earlier in fluctuating - as opposed to constant - warm temperatures (mean = 22°C). This acceleration was not caused by transient VERNALIZATION INSENSITIVE 3-mediated vernalization, differential growth rates or exposure to high temperatures, and was not apparent when the average temperature was cool (mean = 12°C). Further, in constant temperatures, contrary to physiological expectations, these genotypes flowered more rapidly in cool than in warm environments. Fluctuating temperatures often reversed these responses, restoring faster bolting in warm conditions. Independently of bolting time, warm fluctuating temperature profiles also caused morphological changes associated with shade avoidance or 'high-temperature' phenotypes. Our results suggest that previous studies have overestimated the effect of the floral repressor FLC on flowering time by using constant temperature laboratory conditions.

生长与发育的遗传基础通常在恒定的实验室环境中开展研究，但生物体在自然环境中所经历的环境条件往往远为动态多变。本研究探究了每日温度波动、平均温度、日照时长以及春化作用（vernalization），对59个已知存在影响开花时间的等位基因扰动的拟南芥（Arabidopsis thaliana）基因型的开花时间的调控效应。针对部分基因型亚群，本研究还评估了各处理条件对其形态与生长的影响。研究共筛选得到17个基因型，其中多数高表达开花抑制因子FLOWERING LOCUS C（FLC）；相较于恒定升温条件，这些基因型在波动升温（平均温度为22℃）环境下的抽薹时间显著提前。该抽薹加速现象并非由瞬时的VERNALIZATION INSENSITIVE 3（VIN3）介导的春化作用、生长速率差异或高温暴露所引发，且在平均温度较低（12℃）的环境中未出现该效应。此外，在恒定温度条件下，与生理学预期相悖的是，这些基因型在低温环境中的开花速度反而快于温暖环境；而温度波动往往会逆转这类响应，使温暖环境下的抽薹速率恢复更快。除抽薹时间外，升温波动的温度模式还会引发与避荫反应或‘高温’表型相关的形态变化。本研究结果表明，此前的研究因采用恒定温度的实验室培养条件，高估了开花抑制因子FLC对开花时间的调控作用。