Shivhare Radha, Mishra Priyamvada, Badola Poorwa Kamal, Chauhan Puneet Singh, Lata Charu
CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226001, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Plant Cell Rep. 2025 Jun 20;44(7):150. doi: 10.1007/s00299-025-03524-8.
Water stress stimulates plants to regulate flavonoid biosynthesis. Overexpression of the PgF3H gene increases flavonoid levels and drought tolerance in Arabidopsis, with stress-responsive elements in the PgF3H promoter indicating its role in drought response. Water stress significantly impairs plant growth and yield, but plants combat this through various strategies, including flavonoid biosynthesis regulation. Flavonoids, crucial secondary metabolites, aid in plant development and stress responses. Pearl millet, a drought-tolerant crop, produces high levels of secondary metabolites like flavonoids and anthocyanins via the phenylpropanoid pathway. Research indicates that flavonoid-encoding genes are prevalent in drought-tolerant pearl millet variants, hinting at their role in drought response, though their exact functions are not fully understood. This study highlights the essential role of pearl millet flavanone 3-hydroxylase (PgF3H) in flavonoid biosynthesis. To validate this function, PgF3H was expressed in flavonoid-deficient Arabidopsis mutant backgrounds: Atf3h (defective in flavanone 3-hydroxylase activity), Atans (mutated in anthocyanidin synthase, leading to impaired anthocyanin production), and Atanr (a regulatory mutant with altered anthocyanin accumulation). The PgF3H overexpression led to partial or complete restoration of flavonoid production in these mutants, reinforcing the gene's role in biosynthesis and drought resilience. In silico analysis of the PgF3H promoter revealed stress-responsive elements, and ProPgF3H::GUS expressing lines showed increased GUS expression with higher PEG concentrations. The in silico structure of PgF3H revealed a 2OG-Fe(II) oxygenase domain, crucial in the flavonoid biosynthetic pathway. In conclusion, PgF3H overexpression enhances drought tolerance in Arabidopsis, suggesting a potential strategy for improving crop drought resistance by manipulating flavonoid biosynthesis.
水分胁迫刺激植物调节类黄酮生物合成。PgF3H基因的过表达增加了拟南芥中的类黄酮水平和耐旱性，PgF3H启动子中的胁迫响应元件表明其在干旱响应中的作用。水分胁迫显著损害植物生长和产量，但植物通过多种策略应对，包括类黄酮生物合成调节。类黄酮是关键的次生代谢产物，有助于植物发育和胁迫响应。珍珠粟是一种耐旱作物，通过苯丙烷途径产生高水平的次生代谢产物，如类黄酮和花青素。研究表明，类黄酮编码基因在耐旱珍珠粟变种中普遍存在，暗示它们在干旱响应中的作用，尽管其确切功能尚未完全了解。本研究强调了珍珠粟黄烷酮3-羟化酶（PgF3H）在类黄酮生物合成中的重要作用。为了验证这一功能，在缺乏类黄酮的拟南芥突变体背景中表达了PgF3H：Atf3h（黄烷酮3-羟化酶活性有缺陷）、Atans（花青素合酶发生突变，导致花青素产生受损）和Atanr（花青素积累改变的调节突变体）。PgF3H的过表达导致这些突变体中类黄酮产生部分或完全恢复，加强了该基因在生物合成和抗旱性中的作用。对PgF3H启动子的电子分析揭示了胁迫响应元件，ProPgF3H::GUS表达系显示随着PEG浓度升高GUS表达增加。PgF3H的电子结构揭示了一个2OG-Fe(II)加氧酶结构域，这在类黄酮生物合成途径中至关重要。总之，PgF3H的过表达增强了拟南芥的耐旱性，表明通过操纵类黄酮生物合成来提高作物抗旱性的潜在策略。
