“…SWEETs are a class of proteins responsible for transporting sugar across cell membranes, involving in diverse physiological processes of various plant species, such as in reproductive development ( Ge et al, 2000 ; Yang et al, 2006 ; Guan et al, 2008 ), leaf senescence ( Quirino et al, 1999 ; Seo et al, 2011 ), and plant responses to abiotic and biotic stresses in Arabidopsis and rice ( Chu et al, 2006 ; Yang et al, 2006 ; Antony et al, 2010 ; Chen et al, 2010 ; Liu et al, 2011 ). SWEETs genes are evolutionally conserved in both prokaryotes and eukaryotes ( Gamas et al, 1996 ; Artero et al, 1998 ; Chong et al, 2014 ; Jian et al, 2016 ), but plant species possess more SWEETs than that in animals and prokaryotes ( Yuan and Wang, 2013 ). Phylogenetic analysis of plant SWEET genes revealed that they can be grouped into 4 clades as firstly defined in A. thaliana ( Chen et al, 2010 ).…”