Abstract：
Cell wall invertase (CIN) is a vital member of plant invertase (INV) and plays a key role in the breakdown of sucrose. This enzyme facilitates the hydrolysis of sucrose into glucose and fructose, which is crucial for various aspects of plant growth and development. However, the function of CIN genes in foxtail millet (Setaria italica) is less studied. In this research, we used the blast-p of NCBI and TBtools for bidirectional comparison, and a total of 13 CIN genes (named SiCINs) were identified from foxtail millet by using Arabidopsis and rice CIN sequences as reference sequences. The phylogenetic tree analysis revealed that the CIN genes can be categorized into three subfamilies: group 1, group 2, and group 3. Furthermore, upon conducting chromosomal localization analysis, it was observed that the 13 SiCINs were distributed unevenly across five chromosomes. Cis-acting elements of SiCIN genes can be classified into three categories: plant growth and development, stress response, and hormone response. The largest number of cis-acting elements were those related to light response (G-box) and the cis-acting elements related to seed-specific regulation (RY-element). qRT-PCR analysis further confirmed that the expression of SiCIN7 and SiCIN8 in the grain was higher than that in any other tissues. The overexpression of SiCIN7 in Arabidopsis improved the grain size and thousand-grain weight, suggesting that SiCIN7 could positively regulate grain development. Our findings will help to further understand the grain-filling mechanism of SiCIN and elucidate the biological mechanism underlying the grain development of SiCIN.
摘要：
细胞壁转化酶（CIN）是植物转化酶（INV）的重要成员，在蔗糖的分解中起着关键作用。这种酶促进蔗糖水解成葡萄糖和果糖，这对植物生长和发育的各个方面至关重要。然而,谷子（Setariaitalica）中CIN基因的功能研究较少。在这项研究中,我们使用NCBI和TBtools的blast-p进行双向比较，通过使用拟南芥和riceCIN序列作为参考序列，从谷子中鉴定出总共13CIN基因（称为SiCINs）。系统发育树分析表明，CIN基因可分为三个亚家族：第1组，第2组和第3组。此外，在进行染色体定位分析后，观察到13种SiCIN在5条染色体上分布不均。SiCIN基因的顺式作用元件可分为三类：植物生长和发育，应激反应，激素反应。顺式作用元件数量最多的是与光响应相关的元件（G盒）和与种子特异性调节相关的顺式作用元件（RY元件）。qRT-PCR剖析进一步证实SiCIN7和SiCIN8在谷粒中的表达高于在任何其他组织中的表达。SiCIN7在拟南芥中的过表达提高了子粒大小和千粒重,表明SiCIN7可以正向调节籽粒发育。我们的发现将有助于进一步了解SiCIN的籽粒填充机制，并阐明SiCIN籽粒发育的生物学机制。
