Ultraviolet (UV)-B is a component of sunlight and shows a significant effect on DNA damage, which can be regulated by proliferating cell nuclear antigen (PCNA). The role of TaPCNA in wheat (Triticum aestivum L.) programmed cell death (PCD) under UV-B has not been investigated previously. Here, we explored the function of TaPCNA in wheat exposed to UV-B utilising Barley Stripe Mosaic Virus–virus-induced gene silencing (VIGS). The results showed that the expression of TaPCNA was downregulated, and curly wheat leaves with several spots were determined by VIGS. The growth rate and mesophyll cell length were significantly inhibited after TaPCNA was silenced. The activity of superoxide dismutase and the contents of soluble sugar and soluble protein decreased, whereas the activities of peroxidase and catalase and malondialdehyde content increased in TaPCNA-silenced and UV-B treatment groups. DNA laddering and propidium iodide staining results showed that DNA fragments and micronucleus accumulated after TaPCNA silencing with or without UV-B. Thus, TaPCNA participates in plant growth and DNA damage and PCD under UV-B. This study suggests an idea for the exploration of the function of certain genes in such complex wheat genomes and offers a theoretical basis to improve wheat agronomic traits.

紫外线 (UV)-B 是阳光的一种成分，对 DNA 损伤有显着影响，可通过增殖细胞核抗原 (PCNA) 进行调节。TaPCNA 在UV-B 下小麦 ( Triticum aestivum L.) 程序性细胞死亡 (PCD) 中的作用之前尚未研究过。在这里，我们利用大麦条纹花叶病毒 - 病毒诱导的基因沉默（VIGS）探索了 TaPCNA 在暴露于 UV-B 的小麦中的功能。结果表明，TaPCNA表达下调，VIGS 检测出具有多个斑点的卷曲小麦叶片。TaPCNA后生长速度和叶肉细胞长度明显受到抑制被沉默了。TaPCNA沉默组和UV-B处理组超氧化物歧化酶活性、可溶性糖和可溶性蛋白含量降低，而过氧化物酶活性、过氧化氢酶活性和丙二醛含量升高。DNA 梯度和碘化丙啶染色结果表明，在有或没有 UV-B 的情况下，TaPCNA 沉默后 DNA 片段和微核积累。因此，TaPCNA 在 UV-B 下参与植物生长和 DNA 损伤和 PCD。本研究为探索这种复杂的小麦基因组中某些基因的功能提供了思路，并为改善小麦农艺性状提供了理论基础。