Photosynthate partitioning to starch in Arabidopsis thaliana is insensitive to light intensity but sensitive to photoperiod due to a restriction on growth in the light in short photoperiods
Photosynthate partitioning to starch in Arabidopsis thaliana is insensitive to light intensity but sensitive to photoperiod due to a restriction on growth in the light in short photoperiods
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DOI：
10.1111/pce.13000
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发表时间：
2017-11-01
影响因子：
7.3
通讯作者：
Stitt, Mark
中科院分区：
文献类型：
--
作者：
Mengin, Virginie;Pyl, Eva-Theresa;Stitt, Mark
光周期的持续时间可以从前几天预测出来，但辐照度的波动是不可预测的。为了研究淀粉分配如何响应这两个环境变量的变化，在三种不同的光照条件下，在6h和12h的光周期下培养了拟南芥Col-0。随着光周期的缩短和光照强度的增大，淀粉的绝对积累速率增大。光合作用产物分配给淀粉的比例随光周期的缩短而显著增加，但仅在光照强度降低时略有增加。与长光周期相比，在给定光照下，短光周期中白天蔗糖水平略有增加，葡萄糖、果糖和葡萄糖6-磷酸的含量增加了一倍。无论这些糖是对光周期的变化还是对光照的变化做出反应，淀粉积累的速度都与光中的蔗糖和葡萄糖水平密切相关。全株碳收支模型揭示了短光周期对光期生长的选择性限制。有人认为，光周期感知可能与夜间的持续时间有关，它限制了短光周期中光周期的生长，增加了淀粉的分配，并提供了更多的碳储备，以支持长夜中的新陈代谢和生长。
Photoperiod duration can be predicted from previous days, but irradiance fluctuates in an unpredictable manner. To investigate how allocation to starch responds to changes in these two environmental variables, Arabidopsis Col-0 was grown in a 6h and a 12h photoperiod at three different irradiances. The absolute rate of starch accumulation increased when photoperiod duration was shortened and when irradiance was increased. The proportion of photosynthate allocated to starch increased strongly when photoperiod duration was decreased but only slightly when irradiance was decreased. There was a small increase in the daytime level of sucrose and twofold increases in glucose, fructose and glucose 6-phosphate at a given irradiance in short photoperiods compared to long photoperiods. The rate of starch accumulation correlated strongly with sucrose and glucose levels in the light, irrespective of whether these sugars were responding to a change in photoperiod or irradiance. Whole plant carbon budget modelling revealed a selective restriction of growth in the light period in short photoperiods. It is proposed that photoperiod sensing, possibly related to the duration of the night, restricts growth in the light period in short photoperiods, increasing allocation to starch and providing more carbon reserves to support metabolism and growth in the long night.