Tianjin Key Laboratory of Protein Sciences, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin, 300071, China.
Planta. 2023 Aug 19;258(3):68. doi: 10.1007/s00425-023-04219-8.
We found that auxin synthesis gene TAA1 and auxin polar transport genes AUX1 and PIN3 collectively maintain fertility and seed size in Arabidopsis. Auxin plays a vital role in plant gametophyte development and embryogenesis. The auxin synthesis gene TAA1 and the auxin polar transport genes AUX1 and PIN3 are expressed during Arabidopsis gametophyte and seed development. However, aux1, pin3, and taa1 single mutants only exhibit mild reproductive defects. We, therefore, generated aux1-T pin3 taa1-k2 and aux1-T pin3-2 taa1-k1 triple mutants by crossing or CRISPR/Cas9 technique. These triple mutants displayed severe reproductive defects with approximately 70% and 77%, respectively, of the siliques failing to elongate after anthesis. Reciprocal crosses and microscopy analyses showed that the development of pollen and ovules in the aux1 pin3 taa1 mutants was normal, whereas the filaments were remarkably short, which might be the cause of the silique sterility. Further analyses indicated that the development and morphology of aux1 pin3 taa1 seeds were normal, but their size was smaller compared with that of the wild type. These results indicate that AUX1, PIN3, and TAA1 act in concert to maintain fertility and seed size in Arabidopsis.
我们发现生长素合成基因 TAA1 和生长素极性运输基因 AUX1 和 PIN3 共同维持拟南芥的育性和种子大小。生长素在植物配子体发育和胚胎发生中起着至关重要的作用。生长素合成基因 TAA1 和生长素极性运输基因 AUX1 和 PIN3 在拟南芥配子体和种子发育过程中表达。然而，aux1、pin3 和 taa1 单突变体仅表现出轻微的生殖缺陷。因此，我们通过杂交或 CRISPR/Cas9 技术生成了 aux1-T pin3 taa1-k2 和 aux1-T pin3-2 taa1-k1 三重突变体。这些三重突变体表现出严重的生殖缺陷，大约有 70%和 77%的蒴果在开花后不能伸长。正反交和显微镜分析表明，aux1 pin3 taa1 突变体中的花粉和胚珠发育正常，而花丝明显缩短，这可能是蒴果不育的原因。进一步的分析表明，aux1 pin3 taa1 种子的发育和形态正常，但大小比野生型小。这些结果表明，AUX1、PIN3 和 TAA1 协同作用维持拟南芥的育性和种子大小。
