title: Divergent DNA methylation patterns associated with abiotic stress in Hevea brasiliensis.
abstract: Cytosine methylation is a fundamental epigenetic mechanism for gene-expression regulation and development in plants. Here, we report for the first time the identification of DNA methylation patterns and their putative relationship with abiotic stress in the tree crop Hevea brasiliensis (source of 99% of natural rubber in the world). Regulatory sequences of four major genes involved in the mevalonate pathway (rubber biosynthesis pathway) and one general defense-related gene of three high-yielding popular rubber clones grown at two different agroclimatic conditions were analyzed for the presence of methylation. We found several significant variations in the methylation pattern at core DNA binding motifs within all the five genes. Several consistent clone-specific and location-specific methylation patterns were identified. The differences in methylation pattern observed at certain pivotal cis-regulatory sites indicate the direct impact of stress on the genome and support the hypothesis of site-specific stress-induced DNA methylation. It is assumed that some of the methylation patterns observed may be involved in the stress-responsive mechanism in plants by which they adapt to extreme conditions. The study also provide clues towards the existence of highly divergent phenotypic characters among Hevea clones despite their very similar genetic make-up. Altogether, the observations from this study prove beyond doubt that there exist epigenetic variations in Hevea and environmental factors play a significant role in the induction of site-specific epigenetic mutations in its genome.
authors.affiliation: Genome Analysis Lab, Rubber Research Institute of India, Rubber Board PO, Kottayam, Kerala, 686009, India. thomasku79@gmail.com
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Uthup
authors.forename: Minimol
authors.initials: M
authors.lastname: Ravindran
authors.forename: K
authors.initials: K
authors.lastname: Bini
authors.forename: Saha
authors.initials: S
authors.lastname: Thakurdas
mesh_terms: D001947:Breeding; D019295:Computational Biology; D019175:DNA Methylation / Q000235:genetics*; D004262:DNA Restriction Enzymes / Q000378:metabolism; D057890:Epigenomics; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D028482:Hevea / Q000201:enzymology / Q000235:genetics* / Q000502:physiology*; D018895:Microsatellite Repeats / Q000235:genetics; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique; D017422:Sequence Analysis, DNA; D013312:Stress, Physiological / Q000235:genetics*; D013447:Sulfites / Q000378:metabolism
chemical_list: D005819:Genetic Markers; D013447:Sulfites; D004262:DNA Restriction Enzymes; C120301:McrBC endonuclease; C042345:hydrogen sulfite