The exudate resin is collected from a transverse wound mechanically imposed to the bark of the adult tree (bark stripping), followed by application of adjuvant paste on the damage upper line, to promote the biosynthesis and flow of terpenes (Fuller et al., 2016 Rodrigues et al., 2013).Ĭommercial adjuvant pastes are, in general, made of a combination of sulfuric acid (20% v/v) (to prolong wounding and increase oxidative stress) and 3–4.5% of Ethrel (also known as CEPA, 2-chloroethylphosphonic acid), an ethylene precursor that stimulates resin production and flow (McReynolds and Kossuth, 1984 Rodrigues-Corrêa and Fett-Neto, 2012), as well as a carrier material to provide adhesion on the wound (e.g. Under normal growing conditions, pines accumulate between 1 and 5% of their stem mass as resin, but after treatment with chemical elicitors of resinosis the stem oleoresin content generally increases significantly (Rodrigues-Corrêa and Fett-Neto, 2012 Westbrook et al., 2013). elliottii) plantations of the Southeast and South regions (ARESB, 2018). Because it is an easy to obtain, inexpensive and renewable source material, pine resin and its products are used in the production of fungicides, insecticides, fragrances, paints and solvents, adhesives, rubber, biofuels, and especially in fine chemicals such as biodegradable polymers, precursors of drug synthesis and food additives (Neis et al., 2019b Yadav et al., 2015).īrazil is one of the world leaders in pine resin production, mostly based on slash pine ( Pinus elliottii var. The total annual production reaches about 1.2 million tons worldwide, supporting a wide range of multi-billion-dollar industrial applications (Yadav et al., 2015). Pine resin is the raw material for several industrial products and one of the most important non-timber forest products (Neis et al., 2019a,b). The constitutive and induced resin are considered the major chemical defense of conifers, and their composition is a complex, dynamic and variable mixture of terpenoids such as monoterpenes, sesquiterpenes, and diterpenes (Bohlmann and Keeling, 2008 Franceschi et al., 2005 Philipps and Croteau, 1999 Zulak and Bohlmann, 2010). Resin is a viscous fluid exuded from ducts when the tree is under herbivore or pathogen attack (Lange, 2015). These systems include sophisticated constitutive and inducible mechanisms, that involve structural, morphological or physical barriers in all major organs and different tissues (Pascual et al., 2015 Pham et al., 2014 Warren et al., 2015). The adaptive success and co-existence with changing environmental conditions, competing plants, potential pests and foraging animals was only possible due to the acquisition of anatomical and chemical defense systems. Therefore, microtapping can be used for early, rapid, and simple identification of adjuvants with high resin induction capacity and of putative elite individuals for field evaluation, breeding, and clonal propagation.Ĭonifers are the most advanced group of gymnosperms that also include some of the longest living species on the planet, with individual trees often exceeding several hundred years (Warren et al., 2015). High resin-yield individuals were identified by microtapping, and this phenotype was further supported by terpene-related gene expression studies associated with resinosis. All plants were responsive to successive stimuli, just as adult plants. Resin yield increased after the second year. The more lignified basal stems produced more resin than apical ones in the 1-year-old plants. One, two and three-year-old plants consistently increased resinosis when treated with potent adjuvants, mainly methyl jasmonate. Compounds with known effect in adult plants (ethrel, benzoic acid and potassium sulfate) and molecules involved in the transduction of defense signals (methyl jasmonate, salicylic acid, linolenic acid and isoleucine) were evaluated in young plants. elliottii cultivated in greenhouse to extract resin, was evaluated as an alternative to carry out these activities. use of young plants of Pinus elliottii var. Identifying new adjuvants and high resin producing trees in adult forests often requires long time and intense labor. Resin is obtained by wounding the bark of adult trees and applying stimulant pastes with different adjuvants on the wound. Pine resin, a natural source of industrially relevant terpenes, is a major non-wood forestry commodity.
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