Estimation of nuclear genome size and characterization of Ty1-copia like LTR retrotransposon in Mesua ferrea L.

Abstract

Mesua ferrea L. is a multipurpose versatile tree that is well known as a prospective feedstock biodiesel plant. The potentiality of M. ferrea as a sustainable source of feedstock for biodiesel industry is dependent on an extensive knowledge of the genome structure of the plant. However, to date, there has been no genomic research aimed at the exploitation of the biotechnological potential of this species. Flow cytometry with propidium iodide as the DNA stain was used to estimate the nuclear DNA content of Mesua and the 2C value is estimated to be 1.40 ± 0.02 pg. Somatic chromosome count from root-tip cells is found to be 2n = 30 corresponding to the diploid level (n = 15). Fold variation in genome size (1.14) is observed among the plants collected from different geographic locations in Assam and is attributed to reverse transcriptase-RNase H (RT-RH) domains of the Ty1-copia retrotransposons. Dot blot analysis revealed that Ty1-copia accounts for 2.5% of total haploid nuclear genome of Mesua and phylogenetic analyses showed that the RT-RH sequences are heterogeneous and resolved into 3 distinct groups. These results contribute to our understanding about genome organization of Mesua and will provide valuable information for its utilization in future.