Abstract：
CONCLUSIONS: Purine permease PUP11 is essential for rice seed development, regulates the seed setting rate, and influences the cytokinin content, sugar transport, and starch biosynthesis during grain development. The distribution of cytokinins in plant tissues determines plant growth and development and is regulated by several cytokinin transporters, including purine permease (PUP). Thirteen PUP genes have been identified within the rice genome; however, the functions of most of these genes remain poorly understood. We found that pup11 mutants showed extremely low seed setting rates and a unique filled seed distribution. Moreover, seed formation arrest in these mutants was associated with the disappearance of accumulated starch 10 days after flowering. PUP11 has two major transcripts with different expression patterns and subcellular locations, and further studies revealed that they have redundant positive roles in regulating the seed setting rate. We also found that type-A Response Regulator (RR) genes were upregulated in the developing grains of the pup11 mutant compared with those in the wild type. The results also showed that PUP11 altered the expression of several sucrose transporters and significantly upregulated certain starch biosynthesis genes. In summary, our results indicate that PUP11 influences the rice seed setting rate by regulating sucrose transport and starch accumulation during grain filling. This research provides new insights into the relationship between cytokinins and seed development, which may help improve cereal yield.
摘要：
结论：嘌呤通透酶PUP11对水稻种子发育至关重要，调节结实率，影响细胞分裂素的含量，糖运输,和谷物发育过程中的淀粉生物合成。细胞分裂素在植物组织中的分布决定了植物的生长和发育，并受到几种细胞分裂素转运蛋白的调节，包括嘌呤通透酶(PUP)。已在水稻基因组中鉴定出13个PUP基因；然而，大多数这些基因的功能仍然知之甚少。我们发现pup11突变体的结实率极低，种子分布独特。此外，这些突变体的种子形成停滞与开花后10天积累的淀粉消失有关。PUP11有两种主要的转录本，具有不同的表达模式和亚细胞位置，进一步的研究表明，它们在调节结实率方面具有多余的积极作用。我们还发现，与野生型相比，pup11突变体的发育中谷物中的A型反应调节剂（RR）基因上调。结果还显示PUP11改变了几种蔗糖转运蛋白的表达，并显着上调了某些淀粉生物合成基因。总之,我们的结果表明，PUP11通过调节籽粒灌浆过程中的蔗糖运输和淀粉积累来影响水稻结实率。这项研究为细胞分裂素与种子发育之间的关系提供了新的见解，这可能有助于提高谷物产量。
