Preliminary Study on Molecular Mechanism of Variegated Haworthia magnifica Formation

  Objective  Molecular mechanism responsible for the formation of variegated succulent plants, Haworthia magnifica, was investigated using the mutant qj for the comparison.

  Method  Contents of chlorophylls and carotenoids in the plants were determined by spectrophotometry, and gene expression by transcriptome sequencing (RNA-seq).

  Result  The contents of chlorophyll a, chlorophyll b and carotenoids in the variegated qj were significantly lower than those of wild-type H. magnifica. Using RNA-seq, 44 988 938 Reads were obtained for H. magnifica and 37 271 576 for qj which were assembled into 45 226 Unigenes. There were 26 999 Unigenes assigned to Nr annotations, 20 279 to Swissport, 16 943 to KOG categories, and 10 775 to KEGG pathway. A total of 20 305 genes exhibited significantly different expressions that involved 130 pathways, of which 21 significantly differed from the others. The gene expression analysis showed that the genes associated with the chlorophyll synthesis (ko00860), antenna protein (ko00196) and photosynthesis (ko00195) pathways were generally significantly down-regulated.

  Conclusion  The significant variations on the transcriptome sequences, genes and pathways of H. magnifica and its variegated counterpart obtained from this study provided the fundamental information for further study to unveil the underlaying mechanism.