Dear Giridhar,

Please check the pdf attachment for said query.

Best

You can use fungal culture filtrates , bacterial toxins, chitoson salysylic acid Methyl jasmonate, any heavy metals as elicitors.

Dear Giridhar Kalidasu 

Plants are a valuable source of a wide range of secondary metabolites. Despite advancements in synthetic chemistry, biological sources are usually preferred due to lesser side effects and better biodegradability. Plant cells are biosynthetically totipotent and be able to produce the range of chemicals found in the parent plant. This and with other reasons, cell culture technology is found to be advantageous over conventional agricultural production.

Elicitation has been one of the most effective strategies for improving the productivity of bioactive secondary metabolites. Elicitors have been used to stimulate secondary metabolite product formation in plant cell cultures by reducing the process time for increased culture volumes and high product concentrations . Various elicitors such as chitosan, ß-glucan, and yeast extracts, as well as plant hormonal chemicals such as jasmonic acid (JA) and MeJA have been used to induce biotic and abiotic stresses upon plants.

A key to the evaluation of strategies to improve productivity is to carry out that all the problems must be seen in a holistic context. At any rate, substantial progress in improving secondary metabolite production from plant cell cultures has been made within last few years. These new technologies will serve to extend and enhance the continued usefulness of higher plants as renewable sources of chemicals, especially medicinal compounds. We hope that a continuation and intensify cation efforts in this fi eld will lead to controllable and successful biotechnological production of specifi c, valuable, and as yet unknown plant chemicals.

Though, elicitation enhances secondary metabolism in vitro culture of plant cells/organ, but the exact mechanism of elicitationis still not fully understood. Moreover, molecular and biosynthetic pathway of the secondary metabolites should be understood and extensive research must be carried out in this way to determine the optimum conditions for each specific medicinal plant to enhance the secondary metabolites.

As several Mechanisms of Induced Resistance in Plants, viral attenuation and cross protection for plant viruses, most of elicitors interfere with pathways , signaling , Cross-talk , plant defenses signaling Pathways, plant immune system also in gene silence.

Regards

Prof. Houda KAWAS

https://books.google.com/books?id=rMqLAV-ggNMC&pg=PA179&lpg=PA179&dq=cross-talk+in+plant+viruses&source=bl&ots=0uWQuKSHwX&sig=k_5t0XH9zlSTsuSQ3nbDUIw2sUg&hl=ar&sa=X&ved=0ahUKEwjzyaTytaXNAhWkCpoKHa1ZC_UQ6AEIKTAB#v=onepage&q=cross-talk%20in%20plant%20viruses&f=false

http://www.ncbi.nlm.nih.gov/pubmed/18594786

http://www.ijppsjournal.com/Vol6Issue2/8493.pdf

http://www.phytojournal.com/archives/2013/vol2issue2/PartA/9.1.pdf

http://pubag.nal.usda.gov/pubag/downloadPDF.xhtml?id=10343&content=PDF

http://www.symbiosisonlinepublishing.com/biotechnology/biotechnology02.pdf

http://www.sciencedirect.com/science/article/pii/S1319610310001195

http://rstb.royalsocietypublishing.org/content/369/1639/20120281.short

http://aob.oxfordjournals.org/content/89/5/503.full

http://dspace.library.uu.nl/bitstream/handle/1874/7714/piete_01_cross_talk.pdf?sequence=1

Thank you Prof. Houda KAWAS, Srinath Rao and Arvind Singh. Elicitation is widely used to improve plant defence mechanisms. However, little is known about the elicitation of specific desirable compounds like capsaicin in chilli, curcumin in turmeric or piperin in black pepper. There may be general elicitors or elicitors of specific compounds. Elicitors may be the cofactors in the pathways or the organic compounds that interfere with biosynthetic pathways. Apart from many known elicitors, how can we identify a elicitor or for that matter novel elicitors? Please give your opinion. 

 Dear Giridhar, compliments for raising an important point. We are aware plant secondary metabolites are unique sources for pharmaceuticals, food additives, flavors, and other industrial materials. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Understanding signal transduction paths underlying elicitor-induced production of secondary metabolites is important for optimizing their commercial production. How best we can utilize this knowledge for breeding for resistance/ tolerance in crops.

Best wishes

Thank you, Malhotra, sir. I think this approach is huge stake in future quality improvement of spices and medicinal plants.