Caffeine affects adventitious rooting and causes biochemical changes in the hypocotyl cuttings of mung bean (Phaseolus aureus Roxb.)

Abstract

Caffeine (1,3,7-trimethylxanthine), a purine alkaloid found naturally in over 100 plant species, has recently been viewed as a safe chemical for management of pests including molluscs, slugs, snails, bacteria, and as a bird deterrent. It possesses phytotoxicity against plant species, yet the mechanism of action is lacking. A study was conducted to determine the effect of caffeine on the rooting of hypocotyl cuttings of mung bean (Phaseolus aureus) and the associated biochemical changes. At lower concentrations (\1,000 lM) of caffeine, though rooting potential was not affected, yet there was a significant decrease in the number of roots and root length. At 1,000 lM caffeine, there was a 68% decrease in the number of roots/primordia per cutting, whereas root length decreased by over 80%. However, no root formation occurred at 2,000 lM caffeine. Further investigations into the biochemical processes linked to root formation revealed that caffeine significantly affects protein content, activities of proteases, polyphenol oxidases (PPO) and total endogenous phenolic (EP) content, in the mung bean hypocotyls. A decrease in rooting potential was associated with a drastic reduction in protein content in the lower rooted portion, whereas the specific activity of proteases increased indicating that caffeine affects the protein metabolism. Activity of PPO decreased in response to caffeine, whereas EP content increased significantly indicating its non-utilization and thus less or no root formation. Respiratory ability of rooted tissue, as determined through TTC (2,3,5-triphenyl tetrazolium chloride) reduction, was impaired in response to caffeine indicating an adverse effect on the energy metabolism. The study concludes that caffeine interferes with the root development by impairing protein metabolism, affecting activity of PPO (and thus lignification), and EP content, which are the crucial steps for root formation.

Influence of Exogenously Supplemented Caffeine on Cell Division, Germination, and Growth of Economically Important Plants

“…Similar pattern was shown in research on Oryza sativa L. by Smyth [24] who reported 2.5 mM caffeine suppression of shoot elongation by 50% and root elongation by 90%. Also in mung bean (Phaseolus aureus), Batish et al [25] reported that caffeine reduced root number and length produced by hypocotyl cuttings.…”

Response Surface Optimization for Decaffeination and Theophylline Production by Fusarium solani

“…Thus, apart from detoxification of coffee pulp by F. solani, the process could also be used for the production of a value added product like theophylline. Process parameters namely pH (3)(4)(5)(6)(7)(8)(9), temperature (20-40°C) and inoculum size (1-7 × 10 5 spores/ml) were optimized for biodecaffeination by F.solani using RSM. Three responses namely caffeine degradation (Y 1, Y 3, Y 5 ), theophylline formation (Y 2, Y 4, Y 6 ) and 3 methyl xanthine formation (Y 7 ) were evaluated by RSM ( Table 3).…”

“…Disposal of effluents containing caffeine into lakes could cause drinking water to become non-potable [4]. Moreover, the disposal of caffeine wastes into soil could cause infertility by inhibiting seed germination and growth of seedlings [5,6]. These wastes are often released into water bodies or dumped near production sites, causing severe environmental hazard [4,7].…”

Straw preservation effects of Arundo donax L. on its allelopathic activity to toxic and bloom-forming Microcystis aeruginosa

“…Ellipticine as an important plant second metabolite is a kind of topoisomerase II inhibitor, which can mediate the damage process of DNA, and participate in the oxidative phosphorylation uncoupling of mitochondria. Batish et al (2008) pointed out that ellipticine could suppress the rooting process of Phaseolus aureus. IAA is an important plant hormone, which is involved in the growth and differentiation process.…”