Abstract SWEET family genes play an important role in different physiological processes, including sugar transport and adjustments, plant development and environmental adaptability. BLAST tools and Hidden Markov Model-directed sequence alignments in Eucalyptus grandis genome identified 52 Eucalyptus SWEET genes containing MtN3/saliva domain. Out of these, 40 genes encode predicted proteins that have 6 or more transmembrane regions with two MtN3/saliva domains. Six predicted proteins contained only one MtN3/saliva domain, similar to the structure of microbial SemiSWEETs. Of the 52 SWEET candidates, only 45 SWEET family genes were mapped on 8 chromosomes, and most of them showed clustered distribution. The expression profiles revealed that the SWEET genes have different expression in different tissues, showing that they might play different functions in Eucalyptus. Our results explored the evolutionary aspects, provided a systematic description of Eucalyptus SWEET genes and can help researchers to understand the functions of the SWEET family genes in Eucalyptus.

中文翻译：

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桉树（Eucalyptus grandis）SWEET家族基因综合分析

摘要 SWEET 家族基因在糖的转运和调节、植物发育和环境适应性等不同生理过程中发挥着重要作用。BLAST 工具和隐马尔可夫模型导向的 Eucalyptus grandis 基因组序列比对鉴定了 52 个含有 MtN3/saliva 结构域的 Eucalyptus SWEET 基因。其中，40 个基因编码具有 6 个或更多跨膜区域和两个 MtN3/唾液结构域的预测蛋白质。六种预测蛋白质仅包含一个 MtN3/saliva 结构域，类似于微生物 SemiSWEET 的结构。在 52 个 SWEET 候选基因中，只有 45 个 SWEET 家族基因定位在 8 条染色体上，且大部分呈簇状分布。表达谱显示 SWEET 基因在不同组织中的表达不同，表明它们可能在桉树中发挥不同的功能。我们的结果探索了进化方面，提供了桉树SWEET基因的系统描述，可以帮助研究人员了解桉树SWEET家族基因的功能。