Opium poppy (Papaver somniferum) is an important medical plant due to the high amounts of biologically active alkaloids used for production of morphine and codein. The alkaloids are conveniently located in the latex that can easily be obtained from unripe seedpods, but when P. somniferum is cultivated for other purposes than drug production – e.g. poppy seeds – the latex is not desirable. Consequently, the latex-less and low alkaloid cultivar Sujata has been developed by mutation breeding from the latex and alkaloid-rich parent cultivar Sampada. Sujata, however, has weak peduncles/stems and suffers from lodging, and to investigate the underlying cause for this, Ajit Shasany and colleagues from CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India have compared the two cultivars. Anatomical studies revealed that Sujata has approximately only half as many latex-producing lacticifers in the vascular bundles as Sampada. The latex-less cultivar also had significantly lower expression of the cell wall-related gene laccase that by overexpression and RNAi suppression analyses was shown to be involved in ligning biosynthesis. The authors believe that laccase is not involved in laticifer development (which would be plausible since latificers are thought to invade cell walls during development) but solely responsible for the higher lignin production and stronger peduncle/stem in the Sampada cultivar.
Read full article here: Kubásek et al (March 2014) Physiologia Plantarum 150: 436