Cytosolic GSgenes were induced following pathogen infection in tobacco and similar induction occurred in Arabidopsis following infectivity by E. amylovora . Glutamine levels have been also correlated with the activation of defense responses in plants .PAL catalyzes the non-oxidative conversion of phenylalanine to cinnamic acid and ammonia. Also, amidases catalyze the hydrolysis of carboxylic amide bonds to liberate carboxylic acids and ammonia. Presently it is unknown if these defense enzymes are involved in the CT and glufosinate interactions as studied here, but it would be a large and interesting undertaking to study.Weed defense mechanisms against pathogens are important to bioherbicidal efficacy and to interactions of bioherbicides and herbicides. PAL activity can increase dramatically in response to various stimuli . This increase denzyme activity leads to increased production of cinnamic acid, phenolic products and phytoalexins, some of which are toxic to bacteria and fungi.
Another product of PAL catalysis is ammonia. This increased enzyme activity leads to increased production of cinnamic acid, phenolic products and phytoalexins,some of which are toxic to bacteria and fungi. Another product of PALcatalysis is ammonia. Furthermore, PAL was suggested as a target site for herbicides and PAL activity was shown to be elevated or inhibited by variousherbicides.The fungal pathogen Alternaria cassiae,has bioherbicidal activity against sicklepod, and alters phenylpropanoidmetabolism in this weed . PAL activity levels were increased prior tovisual symptoms of pathogenesis when A. cassiae spores were applied to seedlings.PAL activity was elevated 3-fold above uninoculated plants and remained high for several days. Similar results were reported for Alternaria crassa, a fungalbioherbicide that controls jimson weed. Many examples have been reported and summarized with respect to the correlation of PALactivity with pathogen challenge and plant defense e.g. . Nitrilases are involved in a wide variety of biological processes, some related to plant defense and certain amidohydrolases are reported to contribute to the biosynthesis of auxin, the ubiquitous plant growth hormone .
Ammonia and creating an alkaline environment are important in the pathogenesis of some plant pathogens. For example, during colonization of a fungus related to CT, ammonia accumulates in the host plantmaking it more alkaline, thus promoting the activities of extracellular enzymes such as pectate lyase . Similarly, ammonia secretion, modulation of pH toalkaline conditions and ammonia accumulation have been shown to be critical factors related to the pathogenicity of C. coccodes on tomato . Plant pathogens and compounds that alter ammonia in a given host, may interact with pathogenesis. Although some typical effects of CTwere observable in the combined treatment of glufosinate and CT, the degree of toxicity of glufosinateon this bioherbicide may have prevented a synergistic interaction response when these two weed control agents were applied at these concentrations together on hemp sesbania. Possibly, by modifying the relative concentrations of glufosinate and CT, i.e. ,so that the herbicide concentration is lowered,while the CT concentration is raised,might result in synergy. Also,glufosinate could be applied and allowed to be absorbed by the weed for a more extended time, which would effectively reduce the herbicide concentration on the weed surface, and perhaps lower toxicity to CT, thus allowing a higher conidial germination rate, formation of appresoria and infection of this weed host.
Synergy is also a concentration dependent phenomenon, and thus altering the concentration ratio of the components may promote or suppress this outcome.Several Colletotrichum species, have been reported to have synergistic interactions with various herbicides . Synergy was also reported in combinations of glufosinate and two bacterial bioherbicides on some weeds . Cannabis is the most widely used drug in the world. According to the UnitedNations Office on Drugs and Crime, the number of cannabis consumers worldwidewas estimated in 2018 to be 192 million users, with the highest prevalencebeen among young people . Cannabis contains 565 known chemicals, of which 144 are grouped under thename cannabinoids. The major psychoactive ingredient of cannabis is delta9-tetrahydrocannabinol, commonly known as THC. Other cannabinoids present in Indian hemp include delta 8-tetrahydrocannabinol , cannabidiol,cannabinol,cannabicyclol,cannabichromene and cannabigerol.Cannabinoids exert some of their actions by binding to specific receptors: theCB1 cannabinoid receptors, discovered by Devane et al. in 1988 , then cloned by Matsuda et al. in 1990 and the CB2 cannabinoid receptors identified byMunro et al. in 1993 .More than 250 controlled clinical trials have demonstrated their efficacy in a dozen pathologies.