Gao Hongbo, Wu Xiaolei, Zorrilla Cinthya, Vega Sandra E, Palta Jiwan P
College of Horticulture, Hebei Agricultural University, Baoding, China.
Department of Horticulture, University of Wisconsin-Madison, Madison, WI, United States.
Front Plant Sci. 2020 Jan 31;10:1793. doi: 10.3389/fpls.2019.01793. eCollection 2019.
Consistent with reports on other plants we recently reported that a potato transgenic line (AT010901) overexpressing show classic symptoms of calcium deficiency shoot tip injury, leaf curling, leaf margin necrosis and tuber internal defects such as hollow heart and brown spots. The present study was undertaken to quantify calcium in various fraction of leaf and tuber tissues of this transgenic and wild type potato clones to understand the development of these deficiency symptoms at normal calcium nutrition (1mM) and its mitigation at higher calcium nutrition (10mM). Plants were grown in controlled environment growth chamber and watered with balanced nutrient solution containing either 1 or 10 mM calcium. The plants overexpressing showed calcium deficiency symptoms while sequestering calcium in the vacuole as calcium oxalate crystals. Various fractions of calcium were qualified in the young and mature leaves as well as tuber tissue. A reduced concentration of water soluble fraction of calcium was most important factor related to the development of calcium deficiency symptoms in the line overexpressing . Furthermore, an increase in this fraction appear to explain the alleviation of the deficiency symptoms in these transgenic plants.Ours is the first study to document the significance of water-soluble calcium in the development of calcium-deficiency symptoms in the potato transgenic lines overexpressing . Furthermore, our result demonstrates that an increase in this fraction plays a significant role in the alleviation of calcium deficiency symptoms when calcium concentration in the nutrient media is increased. These results provide important insight on the role of in the calcium homeostasis.
与我们最近关于其他植物的报道一致，我们报道了一个过表达的马铃薯转基因系（AT010901）表现出缺钙的典型症状，如茎尖损伤、叶片卷曲、叶缘坏死以及块茎内部缺陷，如空心和褐斑。本研究旨在对该转基因和野生型马铃薯克隆的叶片和块茎组织的不同部分进行钙定量，以了解在正常钙营养（1mM）下这些缺钙症状的发展情况以及在高钙营养（10mM）下症状的缓解情况。植物在可控环境生长室中生长，并用含有1或10mM钙的平衡营养液浇水。过表达的植物表现出缺钙症状，同时将钙以草酸钙晶体的形式隔离在液泡中。对幼叶和成熟叶以及块茎组织中的各种钙组分进行了定量。钙的水溶性组分浓度降低是与过表达系中缺钙症状发展相关的最重要因素。此外，该组分的增加似乎可以解释这些转基因植物中缺钙症状的缓解。我们的研究是首次记录水溶性钙在过表达的马铃薯转基因系缺钙症状发展中的重要性。此外，我们的结果表明，当营养培养基中的钙浓度增加时，该组分的增加在缓解缺钙症状中起重要作用。这些结果为在钙稳态中的作用提供了重要的见解。
