title: Latex-less opium poppy: cause for less latex and reduced peduncle strength.
abstract: A genotype 'Sujata' developed earlier at CSIR-CIMAP from its parent 'Sampada' is considered to be the latex-less variety of Papaver somniferum. These two genotypes are contrasting in terms of latex and stem strength. Earlier we have carried out microarray analysis to identify differentially expressing genes from the capsules of the two genotypes. In this study, the peduncles of the two genotypes were compared for the anatomy revealing less number of laticifers in the cortex and vascular bundles. One of the important cell wall-related genes (for laccase) from the microarray analysis showing significantly higher expression in 'Sampada' capsule was taken up for further characterization in the peduncle here. It was functionally characterized through transient overexpression and RNAi suppression in 'Sujata' and 'Sampada'. The increase in acid insoluble lignin and total lignin in overexpressed tissue of 'Sujata', and comparable decrease in suppressed tissue of 'Sampada', along with corresponding increase and decrease in the transcript abundance of laccase confirm the involvement of laccase in lignin biosynthesis. Negligible transcript in phloem compared to the xylem tissue localized its expression in xylem tissue. This demonstrates the involvement of P. somniferum laccase in lignin biosynthesis of xylem, providing strength to the peduncle/stem and preventing lodging.
authors.affiliation: Biotechnology Division, CSIR-Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow, 226015, UP, India.
authors.forename: Nidarshana
authors.initials: N
authors.lastname: Chaturvedi
authors.forename: Sharad K
authors.initials: SK
authors.lastname: Singh
authors.forename: Ashutosh K
authors.initials: AK
authors.lastname: Shukla
authors.forename: Raj K
authors.initials: RK
authors.lastname: Lal
authors.forename: Madan M
authors.initials: MM
authors.lastname: Gupta
authors.forename: Upendra N
authors.initials: UN
authors.lastname: Dwivedi
authors.forename: Ajit K
authors.initials: AK
authors.lastname: Shasany
mesh_terms: D000595:Amino Acid Sequence; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D042845:Laccase / Q000145:classification / Q000235:genetics / Q000378:metabolism; D007840:Latex / Q000378:metabolism*; D008031:Lignin / Q000378:metabolism; D008969:Molecular Sequence Data; D010207:Papaver / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics / Q000378:metabolism*; D018514:Plant Structures / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D036226:Seedlings / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D052584:Xylem / Q000235:genetics / Q000378:metabolism
chemical_list: D007840:Latex; D010940:Plant Proteins; D008031:Lignin; D042845:Laccase