CmDXS2b

Gene Details:

In the case of DXS, three genes encode functional DXS activities which fall into previously established type I (CmDXS1) and II (CmDXS2a and CmDXS2b) categories, while a fourth DXS-like gene belonging to the type III group did not encode a protein with DXS activity.
Their expression patterns and phylogenies suggest that CmDXS1 is functionally specialized for developmental and photosynthetic processes, while CmDXS2a and CmDXS2b are induced in flowers and ripening fruit of orange- (but not white-) fleshed varieties, coinciding with β-carotene accumulation.
CmDXS1 was expressed in all organs analysed with the exception of roots. By contrast, transcripts for both type II DXS isoforms, CmDXS2a and CmDXS2b, were most abundant in flowers
We report that small-scale gene duplications in the MEP pathway have led to specialized isoforms in melon which play an important role in providing carotenoid precursors during fruit ripening, including the first report of type II DXS proteins involved in this process.