Pandey Prachi, Achary V Mohan Murali, Kalasamudramu Vani, Mahanty Srikrishna, Reddy Guda Maheedhara, Reddy Malireddy K
Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110 067, India,
Plant Cell Rep. 2014 Mar;33(3):435-45. doi: 10.1007/s00299-013-1544-9. Epub 2013 Dec 8.
PgDHAR was isolated from Pennisetum glaucum. PgDHAR responded to abiotic stress and exhibited enzyme activity at broad ranges of temperature, pH and substrate concentrations suggesting its role in stress tolerance.
Dehydroascorbate reductase (EC 1.8.5.1) is a crucial enzyme actively involved in the recycling of ascorbate redox pool in the cellular environment. In this study, the full-length cDNA coding for DHAR polypeptide and its corresponding gene was isolated from Pennisetum glaucum (PgDHAR). PgDHAR encodes a polypeptide of 213 amino acids with a predicted molecular mass of 23.4 kDa and shares 80-75 % sequence homology with DHAR from other plants. The heterologously expressed recombinant PgDHAR protein exhibited activity in a wide range of substrate concentrations. The recombinant PgDHAR is thermostable and retains its activity over a broad pH range. Furthermore, transcript level of PgDHAR is quantitatively up-regulated in response to temperature. On the whole, PgDHAR alone or in combination with other genes of ascorbate-glutathione cycle can be used for the development of stress tolerant as well as nutritionally improved food crop with enhanced ascorbic acid content.
从珍珠粟中分离出了PgDHAR。PgDHAR对非生物胁迫有响应，并且在较宽的温度、pH和底物浓度范围内都表现出酶活性，表明其在胁迫耐受性中发挥作用。
脱氢抗坏血酸还原酶（EC 1.8.5.1）是一种关键酶，积极参与细胞环境中抗坏血酸氧化还原池的循环利用。在本研究中，从珍珠粟（PgDHAR）中分离出了编码DHAR多肽的全长cDNA及其相应基因。PgDHAR编码一个由213个氨基酸组成的多肽，预测分子量为23.4 kDa，与其他植物的DHAR具有80 - 75%的序列同源性。异源表达的重组PgDHAR蛋白在广泛的底物浓度范围内表现出活性。重组PgDHAR具有热稳定性，并且在较宽的pH范围内保持其活性。此外，PgDHAR的转录水平在响应温度时会定量上调。总体而言，单独的PgDHAR或与抗坏血酸 - 谷胱甘肽循环的其他基因结合，可用于培育具有胁迫耐受性以及营养改善、抗坏血酸含量增加的粮食作物。
