Bhattacharjee Soumen, Dey Nivedita
Centre for Advanced Study, Department of Botany, The University of Burdwan, Burdwan, West Bengal India.
Physiol Mol Biol Plants. 2018 Feb;24(1):7-23. doi: 10.1007/s12298-017-0484-1. Epub 2017 Nov 23.
The present work makes an effort to assess and standardize some redox metabolic and molecular parameters for screening drought tolerant indigenous aromatic rice cultivars of West Bengal, India. PEG-induced dehydration stress during early germination caused disruption of redox-homeostasis and oxidative damage in four IARVs (Jamainadu, Tulaipanji, Sitabhog and Badshabhog) by enhancing the accumulation of pro-oxidants [assessed in terms of oxidation of 2',7'-dichlorofluorescindiacetate (DCFDA), accumulation of [Formula: see text] and HO and in situ staining of reactive oxygen species (ROS) in germinating tissue], significant reduction of antioxidative defence (total antioxidant and radical scavenging capacity, total thiol content and activities of antioxidative defence enzymes) and aggravating protein oxidation and lipid peroxidation (assessed in terms of free carbonyl content and accumulation of thiobarbituric acid reactive substances). When compared between the indigenous aromatic rice cultivars, a clear trend in differential redox regulatory properties in which ROS-antioxidant interaction acts at metabolic interface for redox homeostasis was observed in the order Badshabhog > Tulaipanji > Sitabhog > Jamainadu. Moreover, when the efficacy of ascorbate-glutathione cycle for scavenging HO generated during dehydration stress was assessed and compared between the landraces exposed to PEG-induced dehydration stress in germinating tissue, it also exhibited almost the same trend with the landrace Tulaipanji and Badsabhog exhibiting maximum and Jamainadu the minimum efficiencies of the redox cycle. The indigenous aromatic rice cultivars Tulaipanji and Badsabhog resist dehydration stress better than the other two landraces due to its early preparedness to combat oxidative stress by up-regulating expression of genes of some enzymes of ascorbate-glutathione cycle along with some other antioxidative enzymes. A model of redox homeostasis in which ROS-antioxidant (ascorbate-glutathione system) acts at metabolic interface for up-regulation of antioxidative gene expression necessary for differential drought stress tolerance among the indigenous aromatic rice varieties is suggested.
本研究致力于评估和规范一些氧化还原代谢及分子参数，以筛选印度西孟加拉邦耐旱的本土香稻品种。早期萌发期间聚乙二醇（PEG）诱导的脱水胁迫，通过增强促氧化剂的积累[根据2',7'-二氯荧光素二乙酸酯（DCFDA）的氧化、[公式：见原文]和HO的积累以及萌发组织中活性氧（ROS）的原位染色来评估]，导致四个印度香稻品种（Jamainadu、Tulaipanji、Sitabhog和Badshabhog）的氧化还原稳态破坏和氧化损伤，抗氧化防御显著降低（总抗氧化和自由基清除能力、总巯基含量以及抗氧化防御酶的活性），并加剧蛋白质氧化和脂质过氧化（根据游离羰基含量和硫代巴比妥酸反应性物质的积累来评估）。在比较本土香稻品种时，观察到一种明显的差异氧化还原调节特性趋势，即ROS - 抗氧化剂相互作用在代谢界面作用以维持氧化还原稳态，顺序为Badshabhog > Tulaipanji > Sitabhog > Jamainadu。此外，当评估并比较萌发组织中暴露于PEG诱导脱水胁迫的地方品种之间抗坏血酸 - 谷胱甘肽循环清除脱水胁迫期间产生的HO的功效时，也呈现出几乎相同的趋势，地方品种Tulaipanji和Badsabhog表现出最大效率，而Jamainadu的氧化还原循环效率最低。本土香稻品种Tulaipanji和Badsabhog比其他两个地方品种更能抵抗脱水胁迫，这是因为它们通过上调抗坏血酸 - 谷胱甘肽循环的一些酶以及其他一些抗氧化酶的基因表达，更早做好应对氧化应激的准备。提出了一种氧化还原稳态模型，其中ROS - 抗氧化剂（抗坏血酸 - 谷胱甘肽系统）在代谢界面作用，以上调本土香稻品种间差异干旱胁迫耐受性所需的抗氧化基因表达。
