Wheat plants sense substrate volume and root density to proactively modulate shoot growth
Wheat plants sense substrate volume and root density to proactively modulate shoot growth
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DOI：
10.1111/pce.13984
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发表时间：
2020-12-28
影响因子：
7.3
通讯作者：
Bennett, Tom
中科院分区：
文献类型：
--
作者：
Wheeldon, Cara D.;Walker, Catriona H.;Bennett, Tom
植物必须根据当时的环境条件仔细地协调它们的生长和发育。为了做到这一点，植物可以利用一系列营养和非营养信息，使它们能够主动调节自己的生长，以避免资源限制。正如园丁和园艺学家所熟知的那样，基质体积强烈影响植物生长，并且可能是植物非营养信息的关键来源。然而，这些底物体积效应发生的机制尚不清楚。在这里，我们表明小麦植株主动调节其茎的生长相对于基质体积，独立于养分有效性。我们表明，这些效应发生在两个阶段；在第一阶段，稀释可移动的“基质体积感应信号”（SVS），使植物的茎（而不是根）的生长与基质的总大小相匹配，而不管它们的根能占据多少基质。在第二阶段，稀释流动性较低的“根密度感应信号”（RDS），使植物的根生长与实际生根体积相匹配，从而对茎的生长产生相应的影响。研究表明，土壤体积和植物密度的影响在很大程度上是可互换的，植物可以同时使用SVS和RDS来检测它们的邻居，并整合对体积和邻居存在的生长响应。我们的工作证明了植物对其生长做出主动决定的卓越能力，并对减轻农业实践中作物密集播种的影响具有启示意义。
Plants must carefully coordinate their growth and development with respect to prevailing environmental conditions. To do this, plants can use a range of nutritional and non-nutritional information that allows them to proactively modulate their growth to avoid resource limitations. As is well-known to gardeners and horticulturists alike, substrate volume strongly influences plant growth, and maybe a key source of non-nutritional information for plants. However, the mechanisms by which these substrate volume effects occur remain unclear. Here, we show that wheat plants proactively modulate their shoot growth with respect to substrate volume, independent of nutrient availability. We show that these effects occur in two phases; in the first phase, the dilution of a mobile 'substrate volume-sensing signal' (SVS) allows plants to match their shoot (but not root) growth to the total size of the substrate, irrespective of how much of this they can occupy with their roots. In the second phase, the dilution of a less mobile 'root density-sensing signal' (RDS) allows plants to match root growth to actual rooting volume, with corresponding effects on shoot growth. We show that the effects of soil volume and plant density are largely interchangeable and that plants may use both SVS and RDS to detect their neighbours and to integrate growth responses to both volume and the presence of neighbours. Our work demonstrates the remarkable ability of plants to make proactive decisions about their growth, and has implications for mitigating the effects of dense sowing of crops in agricultural practice.