Prathyusha Itikarlapalli Venkata Satya Naga, Chaitanya Kolluru Viswanatha
Department of Biotechnology, GITAM Institute of Technology, GITAM University, Visakhapatnam, 530045, Andhra Pradesh, India.
Biol Futur. 2019 Dec;70(4):312-322. doi: 10.1556/019.70.2019.35. Epub 2019 Dec 1.
Effect of water stress on the physiology and biochemistry of two different Coleus species, Coleus forskholii and Coleus amboinicus, was studied.
Drought stress was imposed by withholding the water supply until leaf water potentials reached -0.4, -0.8, and -1.2 MPa. Physiological parameters such as relative water content and water uptake capacity were studied along with lipid peroxidation, superoxide, HO, and OH accumulation-, l-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging assays. Antioxidant defense system in Coleus under drought stress was studied by quantifying the Trolox equivalent antioxidant capacity, ascorbic acid, reduced glutathione-, and α-tocopherol content as well as activities of superoxide dismutase, catalase, ascorbate peroxidase, peroxidase, and glutathione reductase. Accumulation of osmolytes proline, glycine betaine, and phytohormone abscisic acid was also used as key parameters for assessing their performance.
There was a marked variation in the antioxidative defense system and osmolyte accumulation in these two species under drought stress. Relative water content was reduced and water uptake capacity was increased.
A comparative study in the perspectives of osmolyte accumulation, antioxidant, and physiological responses inferred C. amboinicus as a drought stress-tolerant species when compared to C. forskholii.
研究了水分胁迫对两种不同彩叶草（毛喉鞘蕊花和宽叶彩叶草）生理生化的影响。
通过停止供水来施加干旱胁迫，直至叶片水势达到-0.4、-0.8和-1.2兆帕。研究了相对含水量和水分吸收能力等生理参数，同时进行了脂质过氧化、超氧化物、羟基自由基和氢氧根自由基积累以及1,1-二苯基-2-苦基肼自由基（DPPH）清除试验。通过定量测定特洛克斯等效抗氧化能力、抗坏血酸、还原型谷胱甘肽和α-生育酚含量以及超氧化物歧化酶、过氧化氢酶、抗坏血酸过氧化物酶、过氧化物酶和谷胱甘肽还原酶的活性，研究了干旱胁迫下彩叶草的抗氧化防御系统。渗透调节物质脯氨酸、甘氨酸甜菜碱和植物激素脱落酸的积累也被用作评估它们性能的关键参数。
在干旱胁迫下，这两个物种的抗氧化防御系统和渗透调节物质积累存在显著差异。相对含水量降低，水分吸收能力增加。
从渗透调节物质积累、抗氧化和生理反应的角度进行的比较研究推断，与毛喉鞘蕊花相比，宽叶彩叶草是一种耐旱物种。
