Metabolism and Growth in Arabidopsis Depend on the Daytime Temperature but Are Temperature-Compensated against Cool Nights
Metabolism and Growth in Arabidopsis Depend on the Daytime Temperature but Are Temperature-Compensated against Cool Nights
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DOI：
10.1105/tpc.112.097188
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发表时间：
2012-06-01
期刊：
影响因子：
11.6
通讯作者：
Sulpice, Ronan
中科院分区：
文献类型：
--
作者：
Pyl, Eva-Theresa;Piques, Maria;Sulpice, Ronan
昼夜周期为研究代谢和生长对温度波动的响应提供了一个易于处理的系统。我们推断，对白天和夜晚温度的反应可能会有所不同;虽然白天温度影响光合作用，但夜晚温度会影响光中积累的碳的使用。三个拟南芥加入生长在不同的白天或夜间温度（12至24摄氏度）的碳限制条件下的热循环，并分析生物量，光合作用，呼吸，酶活性，蛋白质水平和代谢产物水平。这些数据被用来模拟碳分配和生长率在光明和黑暗中。白天温度低导致光合作用的抑制和生长的抑制甚至更大。蛋白质含量的普遍增加部分改善了光合作用的抑制。夜间低温对蛋白质含量、淀粉周转率或生长没有影响。在温暖的夜晚，碳的使用能力过剩。我们建议，这种能力的使用受到反馈抑制的限制，这是放松在夜间温度较低，从而缓冲增长对夜间温度的波动。例如，淀粉降解的速率完全是温度补偿的，即使是温度的突然变化，并且当夜间温度降低时，多核糖体负载增加。
Diurnal cycles provide a tractable system to study the response of metabolism and growth to fluctuating temperatures. We reasoned that the response to daytime and night temperature may vary; while daytime temperature affects photosynthesis, night temperature affects use of carbon that was accumulated in the light. Three Arabidopsis thaliana accessions were grown in thermocycles under carbon-limiting conditions with different daytime or night temperatures (12 to 24 degrees C) and analyzed for biomass, photosynthesis, respiration, enzyme activities, protein levels, and metabolite levels. The data were used to model carbon allocation and growth rates in the light and dark. Low daytime temperature led to an inhibition of photosynthesis and an even larger inhibition of growth. The inhibition of photosynthesis was partly ameliorated by a general increase in protein content. Low night temperature had no effect on protein content, starch turnover, or growth. In a warm night, there is excess capacity for carbon use. We propose that use of this capacity is restricted by feedback inhibition, which is relaxed at lower night temperature, thus buffering growth against fluctuations in night temperature. As examples, the rate of starch degradation is completely temperature compensated against even sudden changes in temperature, and polysome loading increases when the night temperature is decreased.