Invertases catalyze the irreversible hydrolysis of sucrose into glucose and fructose and thus play key roles in carbon metabolism and plant development. To gain insights into their evolutional and functional relationships, we conducted genome-wide analyses of invertase genes in tomato and other species, focusing on their evolution and expression dynamics. The analyses unexpectedly identified in the tomato genome 5 pseudo invertsase sequences and 5 non-functional cell wall invertases (CWINs) lacking the critical β-fructosidase motif or other amino acids required for hydrolyzing sucrose. Based on their phylogeny relationship and exon–intron structure, we speculated that the invertase gene family could arose from different ancestral genes. The acid invertase gene family, comprised of CWIN and vacuolar invertase (VIN), expanded through segmental and tandem duplication. Analysis of functional divergence suggests site-specific shifted evolutionary rate (Type-I) have played an important role in evolutionary novelties after acid invertase gene duplication in plants. Finally, paralogs within each of the CWIN, VIN and CIN subfamilies exhibited diverse expression responses to the same set of stress treatments including salt and temperature stresses, probably reflecting functional adaptability of the invertase genes during evolution.

中文翻译：

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番茄转化酶基因家族进化和表达动力学的新见解

转化酶催化蔗糖不可逆地水解为葡萄糖和果糖，因此在碳代谢和植物发育中起关键作用。为了深入了解它们的进化和功能关系，我们对番茄和其他物种中的转化酶基因进行了全基因组分析，重点是它们的进化和表达动态。分析出乎意料地在番茄基因组中发现了 5 个假转化酶序列和 5 个缺乏关键 β-果糖苷酶基序或水解蔗糖所需的其他氨基酸的无功能细胞壁转化酶 (CWIN)。基于它们的系统发育关系和外显子-内含子结构，我们推测转化酶基因家族可能来自不同的祖先基因。酸性转化酶基因家族，包括 CWIN 和液泡转化酶 (VIN)，通过分段和串联复制扩展。功能差异分析表明，位点特异性转移进化速率（I 型）在植物酸性转化酶基因复制后的进化新颖性中发挥了重要作用。最后，每个 CWIN、VIN 和 CIN 亚家族中的旁系同源物对同一组胁迫处理（包括盐和温度胁迫）表现出不同的表达反应，这可能反映了转化酶基因在进化过程中的功能适应性。