Xia Chuan, Wang Yu-Jiao, Liang Yan, Niu Qian-Kun, Tan Xiao-Yun, Chu Liang-Cui, Chen Li-Qun, Zhang Xue-Qin, Ye De
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China; Key Laboratory of Crop Germplasm Resources and Utilization, Ministry of Agriculture, The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Plant J. 2014 Sep;79(5):741-56. doi: 10.1111/tpj.12582. Epub 2014 Jul 23.
In flowering plants, male gametes (sperm cells) develop within male gametophytes (pollen grains) and are delivered to female gametes for double fertilization by pollen tubes. Therefore, pollen tube growth is crucial for reproduction. The mechanisms that control pollen tube growth remain poorly understood. In this study, we demonstrated that the ARID-HMG DNA-binding protein AtHMGB15 plays an important role in pollen tube growth. This protein is preferentially expressed in pollen grains and pollen tubes and is localized in the vegetative nuclei of the tricellular pollen grains and pollen tubes. Knocking down AtHMGB15 expression via a Ds insertion caused retarded pollen tube growth, leading to a significant reduction in the seed set. The athmgb15-1 mutation affected the expression of 1686 genes in mature pollen, including those involved in cell wall formation and modification, cell signaling and cellular transport during pollen tube growth. In addition, it was observed that AtHMGB15 binds to DNA in vitro and interacts with the transcription factors AGL66 and AGL104, which are required for pollen maturation and pollen tube growth. These results suggest that AtHMGB15 functions in pollen tube growth through the regulation of gene expression.
在开花植物中，雄配子（精子细胞）在雄配子体（花粉粒）中发育，并通过花粉管传递给雌配子以进行双受精。因此，花粉管生长对繁殖至关重要。控制花粉管生长的机制仍知之甚少。在本研究中，我们证明了ARID-HMG DNA结合蛋白AtHMGB15在花粉管生长中起重要作用。该蛋白在花粉粒和花粉管中优先表达，并定位于三细胞花粉粒和花粉管的营养核中。通过Ds插入敲低AtHMGB15的表达导致花粉管生长迟缓，从而导致结实率显著降低。athmgb15-1突变影响了成熟花粉中1686个基因的表达，包括那些参与花粉管生长过程中细胞壁形成和修饰、细胞信号传导和细胞运输的基因。此外，观察到AtHMGB15在体外与DNA结合，并与花粉成熟和花粉管生长所需的转录因子AGL66和AGL104相互作用。这些结果表明，AtHMGB15通过调节基因表达在花粉管生长中发挥作用。
