~ 19 ~ The Pharma Innovation Journal 2019; 8(1): 19-22 ISSN (E): 2277- 7695 ISSN (P): 2349-8242 NAAS Rating: 5.03 TPI 2019; 8(1): 19-22 © 2019 TPI www.thepharmajournal.com Received: 13-11-2018 Accepted: 15-12-2018 Shilpi Rajput Department of Botany, University of Rajasthan, Jaipur, Rajasthan, India Payal Lodha Department of Botany, University of Rajasthan, Jaipur, Rajasthan, India Correspondence Shilpi Rajput Department of Botany, University of Rajasthan, Jaipur, Rajasthan, India Histochemical localization of lipids, and lignin in healthy and Meloidogyne incognita, infected sunflower (Helianthus annuus Linn.) Shilpi Rajput and Payal Lodha Abstract The root knot nematodes, belonging to the genus Meloidogyne, which have a wide host range, are the deadliest enemy of vegetable crops and a pest of crucial economic importance. These produce conspicuous galls on the roots and the infestations can be recognized easily in fields. It is very common and abundant in the sandy soils of Jaipur and adjoining areas. In Jaipur district, Sunflower an economically important vegetable crop was found infested with highly pathogenic Meloidogyne incognita. Histochemical tests were applied to localize lipids and lignins in the diseased and healthy root tissues. The metabolites viz. lipids and lignins were found more in galled roots as compared to healthy roots. Keywords: Meloidogyne incognita, histochemical localization, root knot nematode, sunflower, metabolites Introduction Human kind depends in a myriad ways on plant and plant products. The quest for new plant products and new methods of using them to satisfy the emerging needs is an ever expanding enterprise. Unfortunately, these plants become the victim of many disease causing micro- organisms including the plant parasitic nematodes which can bring about disruption in the physiological equilibrium of the attacked plants. The plants, in turn, react in a number of ways to off-set these disturbances and the overall plant response determines, to a large extent, the success or failure of the interactions. For a better understanding of various histopathological changes that occurred as a result of nematode infection, in situ localization of various metabolites was helpful. Although, some pathogens used mechanical force to penetrate plant tissues but subsequent development of disease syndrome was dependent on histochemical alterations and biochemical reactions taking place between substances secreted by the pathogens and those already present or produced by the host as a response to the infection. Histochemical techniques were advantageous as they enabled in situ localization of various metabolites at the site of their synthesis or action. While information is available on morphological and biochemical changes that occur in plants invaded by endoparasitic nematodes, little work has been done with a histochemical technique. Since the anatomical area that is biochemically affected by such nematode infections may be quite small, it is imperative that histochemical techniques be employed, lest the effects of infection be lost by dilution from non-affected cells. After histochemically studying the soybean roots infected by Meloidogyne sp., it was reported that giant cell walls contained cellulose and pectin but lacked lignin, suberin, starch or ninhydrin positive substances (Dropkin and Nelson, 1960) [9] . It was observed that M. javanica induced giant cell in tomato contained traces of carbohydrates and fats but it was particularly rich in protein and RNA. The large irregularly shaped nuclei contained a large nucleolus and a number of feulgen-positive bodies, scattered irregularly along the nuclear envelope (Bird, 1961) [2] . It was reported that in ginger infected with root-knot nematode, giant cell nuclei and cytoplasm were rich in nucleic acids. Starch was absent in the giant cells and in the cells of the infected region of the rhizome. Giant cells showed the presence of minute protein granules. The outer side of the egg sac consisted of a thick layer of insoluble polysaccharides (Shah and Raju, 1977) [20] .