Departamento de Nutrición Vegetal, CEBAS-CSIC, 30100 Murcia, Spain.
Physiol Plant. 2019 Feb;165(2):264-276. doi: 10.1111/ppl.12827. Epub 2018 Oct 15.
Potassium (K ) is a macronutrient known for its high mobility and positive charge, which allows efficient and fast control of the electrical balance and osmotic potential in plant cells. Such features allow K to remarkably contribute to plant stress adaptation. Some agricultural lands are deficient in K , imposing a stress that reduces crop yield and makes fertilization a common practice. However, individual stress conditions in the field are rare, and crops usually face a combination of different stresses. As plant response to a stress combination cannot always be deduced from individual stress action, it is necessary to gain insights into the specific mechanisms that connect K homeostasis with other stress effects to improve plant performance in the context of climate change. Surprisingly, plant responses to environmental stresses under a K -limiting scenario are poorly understood. In the present review, we summarize current knowledge and find substantial gaps regarding specific outcomes of K deficiency in addition to other environmental stresses. In this regard, combined nutrient deficiencies of K and other macronutrients are covered in the first part of the review and interactions arising from K deficiency with salinity, drought and biotic factors in the second part. Information available so far suggests a prominent role of potassium and nitrate transport systems and their regulatory proteins in the response of plants to several stress combinations. Thus, such molecular pathways, which are located at the crossroad between K homeostasis and environmental stresses, could be considered biotechnological targets in future studies.
钾（K）是一种大量营养素，以其高流动性和正电荷而闻名，这使其能够有效地快速控制植物细胞的电平衡和渗透势。这些特性使 K 能够显著促进植物适应压力。一些农业用地缺乏 K，造成压力，降低作物产量，施肥成为常见做法。然而，田间的个别压力条件很少见，作物通常面临多种不同压力的组合。由于植物对压力组合的反应不能总是从单个压力作用中推断出来，因此有必要深入了解将 K 稳态与其他压力效应联系起来的特定机制，以提高植物在气候变化背景下的性能。令人惊讶的是，在 K 限制情况下植物对环境压力的反应还知之甚少。在本综述中，我们总结了当前的知识，并发现了在 K 缺乏以及其他环境压力之外的具体结果方面存在很大差距。在这方面，综述的第一部分涵盖了 K 和其他大量营养素联合缺乏的情况，第二部分涵盖了 K 缺乏与盐度、干旱和生物因素相互作用的情况。到目前为止的信息表明，钾和硝酸盐转运系统及其调节蛋白在植物对多种压力组合的反应中起着重要作用。因此，这些位于 K 稳态和环境压力交叉点的分子途径可以在未来的研究中被视为生物技术目标。
