Calcium-dependent protein kinases (CDPKs) are essential regulators of plant growth and development, biotic and abiotic stress responses. Inactivation of the auto-inhibitory domain (AID) of CDPKs provides the constitutive activity. This study investigated the effect of overexpressed native and constitutive active (AtCPK1-Ca) forms of the AtCPK1 gene on abiotic stress tolerance and the ROS/redox system in Rubia cordifolia transgenic callus lines. Overexpression of the native AtCPK1 increased tolerance to salinity and cold almost in two times, when AtCPK1-Ca – in three times compare to control culture. A more interesting effect of overexpression of the AtCPK1 and AtCPK1-Ca was observed for heat resistance. The native form of AtCPK1 increased resistance to heating by 45%, while the AtCPK1-Ca increased by 80%. At the same time, another type of mutation of the AID (AtCPK1-Na, not active) did not affect the tolerance of the cell culture to stresses. We suppose, in this process, the ROS/redox system might be involved. Levels of intracellular ROS, ROS-generating enzymes expression and activities (Rbohs, Prx) and ROS-detoxifying enzymes (SOD, Cat, Apx and Prx) changed in a coordinated manner and in strict interconnection, depending of the callus growth phase and correlated with improved stress tolerance caused by AtCPK1. Because overexpression of both the AtCPK1 and AtCPK1-Ca did not significantly change callus growth, we propose that inactivation of AID of the AtCPK1 or its ortholog, might be an interesting instrument for improvement of plant cells resistance to abiotic stress.

钙依赖性蛋白激酶（CDPKs）是植物生长与发育，生物和非生物胁迫反应的重要调节剂。CDPKs的自抑制域（AID）的失活提供了组成性活性。这项研究调查了AtCPK1基因过表达的天然和本构活性（AtCPK1-Ca）形式对非生物胁迫耐受性和茜草转基因愈伤组织中ROS /氧化还原系统的影响。与对照培养相比，当AtCPK1-Ca时，天然AtCPK1的过表达几乎两倍提高了对盐度和寒冷的耐受性。AtCPK1和AtCPK1过表达的更有趣的效果-观察到Ca的耐热性。天然形式的AtCPK1将耐热性提高了45％，而AtCPK1 - Ca的耐热性提高了80％。同时，AID的另一种突变（AtCPK1-Na，未激活）不影响细胞培养物对压力的耐受性。我们假设在此过程中可能涉及ROS /氧化还原系统。细胞内ROS，ROS产生酶的表达和活性（Rbohs，Prx）和ROS解毒酶（SOD，Cat，Apx和Prx）的水平以协调的方式和严格的相互关系发生变化，具体取决于愈伤组织的生长阶段，并且与由AtCPK1改善的耐压性。因为AtCPK1和AtCPK1-Ca的过表达都不会显着改变愈伤组织的生长，所以我们建议灭活AtCPK1或其直系同源物的AID可能是改善植物细胞对非生物胁迫抗性的有趣手段。