Soil and Crop Sciences Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA.
Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan 611130, China.
Plant Physiol. 2021 May 27;186(1):655-676. doi: 10.1093/plphys/kiab054.
Addressing the looming global food security crisis requires the development of high-yielding crops. In agricultural soils, deficiency in the micronutrient copper significantly decreases grain yield in wheat (Triticum aestivum), a globally important crop. In cereals, grain yield is determined by inflorescence architecture, flower fertility, grain size, and weight. Whether copper is involved in these processes, and how it is delivered to the reproductive organs is not well understood. We show that copper deficiency alters not only the grain set but also flower development in both wheat and its recognized model, Brachypodium distachyon. We then show that the Brachypodium yellow stripe-like 3 (YSL3) transporter localizes to the phloem, transports copper in frog (Xenopus laevis) oocytes, and facilitates copper delivery to reproductive organs and grains. Failure to deliver copper, but not iron, zinc, or manganese to these structures in the ysl3 CRISPR-Cas9 mutant results in delayed flowering, altered inflorescence architecture, reduced floret fertility, grain size, weight, and protein accumulation. These defects are rescued by copper supplementation and are complemented by YSL3 cDNA. This knowledge will help to devise sustainable approaches for improving grain yield in regions where soil quality is a major obstacle for crop production. Copper distribution by a phloem-localized transporter is essential for the transition to flowering, inflorescence architecture, floret fertility, size, weight, and protein accumulation in seeds.
解决迫在眉睫的全球粮食安全危机需要开发高产作物。在农业土壤中，微量营养素铜的缺乏会显著降低小麦（Triticum aestivum）的谷物产量，小麦是一种全球重要的作物。在谷类作物中，谷物产量由花序结构、花的育性、籽粒大小和重量决定。铜是否参与这些过程，以及它如何被输送到生殖器官尚不清楚。我们表明，铜缺乏不仅改变了籽粒结实率，还改变了小麦及其公认模式植物短柄草（Brachypodium distachyon）的花发育。然后我们表明，Brachypodium 类黄酮 3（YSL3）转运蛋白定位于韧皮部，在青蛙（Xenopus laevis）卵母细胞中运输铜，并促进铜向生殖器官和籽粒的输送。在 ysl3 CRISPR-Cas9 突变体中，未能将铜而不是铁、锌或锰输送到这些结构中，导致开花延迟、花序结构改变、小花育性降低、籽粒大小、重量和蛋白质积累减少。这些缺陷可以通过铜补充来挽救，并可以通过 YSL3 cDNA 来互补。这些知识将有助于设计在土壤质量是作物生产主要障碍的地区提高谷物产量的可持续方法。由韧皮部定位的转运蛋白分配铜对于开花、花序结构、小花育性、大小、重量和种子中蛋白质积累的转变至关重要。
