Wong Gwo Rong, Chua Kah Ooi, Rahim Aida Nabila, Kaliapan Kausalyaa, Harikrishna Jennifer Ann, Ramakrishnan Narayanan, Mazumdar Purabi
Centre for Research in Biotechnology for Agriculture, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
Institute for Advanced Studies, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
Plant Cell Rep. 2025 Sep 22;44(10):217. doi: 10.1007/s00299-025-03604-9.
This study reveals transcriptomic reprogramming in tomato under UV-C, highlighting enriched defence pathways, calcium signalling, enhanced pathogen tolerance, increased defence enzyme activity, and photoreceptor-mediated UV-C perception, linking light signalling to stress adaptation. UV-C radiation, when applied at hormetic dosage, acts as a mild abiotic stressor in plants, triggering beneficial responses that enhance yield and bioactive compound production. However, transcriptomic responses to UV-C remain underexplored. This study investigates UV-C-induced transcriptomic changes in two tomato cultivars with differing UV-C susceptibility; Red Rock (susceptible) and Super Star (comparatively tolerant). RNA-seq analysis revealed 3540 DEGs in Red Rock and 2678 in Super Star, with a higher proportion of up-regulated genes in both cultivars after UV-C exposure. GO analysis indicated a conserved response, with enriched pathways associated with defence and stress adaptation. KEGG and PGSEA analyses highlighted significant enrichment in phenylpropanoid biosynthesis, plant-pathogen interaction, and fatty acid degradation pathways. Calcium-binding and signalling genes were predominantly up-regulated, suggesting a key role in UV-C-induced defence responses. RT-qPCR analysis of 17 selected genes, in both cultivars, showed the highest change in expression for Solyc06g069740.1, encoding a calcium-binding EF-hand family protein involved in signal transduction and Solyc05g050350.2, a Cyclic nucleotide-gated ion channel 1 involved in ion transport across the membrane during defence response. Detached leaf assays with Botrytis cinerea and Sclerotinia sclerotiorum demonstrated enhanced pathogen tolerance in UV-C-treated plants, with reduced lesion sizes and increased defence enzyme activity, including chitinase, phenylalanine ammonia-lyase, β-1,3-glucanase, and polyphenol oxidase, compared to fungal-treated controls. Further analysis of photoreceptors revealed upregulation of UV Resistance Locus 8 and Cryptochromes, linking UV-C perception to downstream signalling. These findings provide insights into UV-C-induced defence mechanisms and potential applications for improving crop resilience and productivity.
本研究揭示了番茄在UV-C处理下的转录组重编程，突出了富集的防御途径、钙信号传导、增强的病原体耐受性、增加的防御酶活性以及光感受器介导的UV-C感知，将光信号传导与胁迫适应联系起来。当以刺激剂量施加UV-C辐射时，它在植物中作为一种温和的非生物胁迫因子，引发有益反应，提高产量和生物活性化合物的产生。然而，对UV-C的转录组反应仍未得到充分研究。本研究调查了UV-C诱导的两个对UV-C敏感性不同的番茄品种（红岩（敏感）和超级明星（相对耐受））的转录组变化。RNA测序分析显示，红岩中有3540个差异表达基因（DEG），超级明星中有2678个，两个品种在UV-C处理后上调基因的比例更高。基因本体（GO）分析表明存在保守反应，与防御和胁迫适应相关的途径富集。京都基因与基因组百科全书（KEGG）和基因集富集分析（PGSEA）突出了苯丙烷生物合成、植物-病原体相互作用和脂肪酸降解途径中的显著富集。钙结合和信号基因主要上调，表明在UV-C诱导的防御反应中起关键作用。对两个品种中17个选定基因的逆转录定量聚合酶链反应（RT-qPCR）分析显示，编码参与信号转导的钙结合EF手家族蛋白的Solyc06g069740.1和参与防御反应期间跨膜离子运输的环核苷酸门控离子通道1的Solyc05g050350.2的表达变化最大。用灰葡萄孢和核盘菌进行的离体叶片试验表明，与真菌处理的对照相比，UV-C处理的植物对病原体的耐受性增强，病斑大小减小，防御酶活性增加，包括几丁质酶、苯丙氨酸解氨酶、β-1,3-葡聚糖酶和多酚氧化酶。对光感受器的进一步分析显示，紫外线抗性位点8和隐花色素上调，将UV-C感知与下游信号传导联系起来。这些发现为UV-C诱导的防御机制以及提高作物抗逆性和生产力的潜在应用提供了见解。
