Comprehensive analysis ofSWEETfamily genes inEucalyptus(Eucalyptus grandis)

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 inEucalyptus grandisgenome identified 52EucalyptusSWEET 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 inEucalyptus. Our results explored the evolutionary aspects, provided a systematic description ofEucalyptusSWEET genes and can help researchers to understand the functions of the SWEET family genes inEucalyptus.