Dipartimento di Scienze della Vita, University of Siena, via Mattioli 4, 53100 Siena, Italy.
Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Bologna, via Irnerio 42, 40126 Bologna, Italy.
Cells. 2024 May 15;13(10):840. doi: 10.3390/cells13100840.
Pollen, the male gametophyte of seed plants, is extremely sensitive to UV light, which may prevent fertilization. As a result, strategies to improve plant resistance to solar ultraviolet (UV) radiation are required. The tardigrade damage suppressor protein (Dsup) is a putative DNA-binding protein that enables tardigrades to tolerate harsh environmental conditions, including UV radiation, and was therefore considered as a candidate for reducing the effects of UV exposure on pollen. Tobacco pollen was genetically engineered to express Dsup and then exposed to UV-B radiation to determine the effectiveness of the protein in increasing pollen resistance. To establish the preventive role of Dsup against UV-B stress, we carried out extensive investigations into pollen viability, germination rate, pollen tube length, male germ unit position, callose plug development, marker protein content, and antioxidant capacity. The results indicated that UV-B stress has a significant negative impact on both pollen grain and pollen tube growth. However, Dsup expression increased the antioxidant levels and reversed some of the UV-B-induced changes to pollen, restoring the proper distance between the tip and the last callose plug formed, as well as pollen tube length, tubulin, and HSP70 levels. Therefore, the expression of heterologous Dsup in pollen may provide the plant male gametophyte with enhanced responses to UV-B stress and protection against harmful environmental radiation.
花粉是种子植物的雄性配子体,对紫外线极为敏感,这可能会阻止受精。因此,需要采取策略来提高植物对太阳紫外线 (UV) 辐射的抵抗力。缓步动物损伤抑制蛋白 (Dsup) 是一种假定的 DNA 结合蛋白,使缓步动物能够耐受恶劣的环境条件,包括紫外线辐射,因此被认为是减少紫外线对花粉影响的候选蛋白。我们通过基因工程使烟草花粉表达 Dsup,然后使其暴露于 UV-B 辐射下,以确定该蛋白在提高花粉抗性方面的有效性。为了确定 Dsup 在预防 UV-B 胁迫方面的作用,我们对花粉活力、萌发率、花粉管长度、雄性生殖单位位置、胼胝质塞发育、标记蛋白含量和抗氧化能力进行了广泛的研究。结果表明,UV-B 胁迫对花粉粒和花粉管生长都有显著的负面影响。然而,Dsup 的表达增加了抗氧化水平,并逆转了部分 UV-B 诱导的花粉变化,恢复了花粉尖端和最后一个形成的胼胝质塞之间的适当距离,以及花粉管长度、微管蛋白和 HSP70 水平。因此,异源 Dsup 在花粉中的表达可能为植物雄性配子体提供对 UV-B 胁迫的增强响应和对有害环境辐射的保护。