Enzymatic Activities and Gene Transcript Levels Associated with the Augmentation of Antioxidant Constituents during Drought Stress in Lettuce
Enzymatic Activities and Gene Transcript Levels Associated with the Augmentation of Antioxidant Constituents during Drought Stress in Lettuce
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DOI：
10.3390/horticulturae7110444
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发表时间：
2021-11-01
期刊：
影响因子：
3.1
通讯作者：
Uno, Yuichi
中科院分区：
文献类型：
--
作者：
Koyama, Ryohei;Yoshimoto, Aika;Uno, Yuichi
研究了有效的栽培方法，以促进植物工厂产品品牌化。适度的胁迫可以增强对人类健康有益的植物成分，而不会降低产量。脱水胁迫增加了莴苣根际抗氧化剂的含量，包括l -抗坏血酸（AsA）和多酚。本研究探讨了影响抗氧化成分增加的主要因素。干旱处理导致亲水性氧自由基吸收能力（ORAC）值增加，而疏水性ORAC值没有增加。抗氧化酶（超氧化物歧化酶，SOD，抗坏血酸过氧化物酶，APX）活性在干旱条件下均升高。RNA-seq分析发现33个差异表达基因上调，115个差异表达基因下调，40个基因本体富集类别。在干旱胁迫下，脱氢基因的表达最为显著。脱水素通过清除自由基和保护酶等多种功能保护植物细胞免受干燥。实时荧光定量PCR证实，随着根的干燥，一些脱水因子显著增加。综上所述，干旱胁迫下抗氧化水平的提高可能不是由于抗氧化酶基因的诱导，而是由于酶活性的增加。这些活动可能受到干旱胁迫下由上调的类似物编码的脱氢酶的保护。
Efficient cultivation methods were investigated to promote the branding of products in plant factories. Moderate stress can enhance plant constituents that are beneficial for human health, without reducing yield. Dehydration stress in lettuce rhizospheres increased some antioxidants, including L-ascorbic acid (AsA) and polyphenols. In this study, the major factors contributing to the augmentation of antioxidant constituents were investigated. The drought treatment resulted in increased hydrophilic oxygen radical absorbance capacity (ORAC) values but not hydrophobic ORAC values. Both activities of antioxidant enzymes (superoxide dismutase, SOD, and ascorbate peroxidase, APX) were elevated under drought conditions. RNA-seq analysis revealed 33 upregulated and 115 downregulated differentially expressed genes, and 40 gene ontology enrichment categories. A dehydrin gene was the most significant among the upregulated genes in response to drought stress. Dehydrin protects plant cells from dryness through multiple functions, such as radical scavenging and protection of enzymes. Real-time PCR validated the substantial increase in some dehydrin paralogs with root desiccation. In conclusion, the enhancement of antioxidant levels by drought stress is likely not due to the induction of antioxidant enzyme genes, but due to increased enzymic activities. These activities might be protected by dehydrins encoded by the upregulated paralogs under drought stress.