Physiological cost of induced resistance in cotton plants at different nitrogen levels

Abstract

There is a large number of challenges regarding the control of plant diseases in the 21 st century. The use of chemicals has currently become restricted due to problems caused to the environment, as well as the high costs involved and the potential risk of the emergence of pathogen RESUMO ABSTRACTResistance induction through the use of chemical inducers often results in physiological costs to the plant. In this study, induced resistance in cotton plants was evaluated with regard to physiological costs in a cultivar susceptible to Colletotrichum gossypii var. cephalosporioides (CNPA GO 2002 -7997). Plants were cultivated in substrates with two levels of nitrogen and received two applications of acibenzolar-S-methyl (ASM), jasmonic acid (JA) and Agro-M os ® ( AM ) d i s e a s e r e s i s t a n c e i n d u c e r s . P l a n t h e i g h t ( H ) , internodal length (IL), shoot fresh weight (SFW), root fresh weight (RFW), shoot dry weight (SDW) and root dry weight (RDW) were evaluated. The activity of the phenylalanine ammonia lyase (PAL) and peroxidase (POX) was also determined. The plants treated with ASM presented high physiological costs with an accentuated reduction in H, SFW and SDW, whereas those treated with JA Barbosa, M.A.G.; Laranjeira, D.; Coelho, R.S.B. Physiological cost of induced resistance in cotton plants at different nitrogen levels. Summa Phytopathologica, v.34, n.4, p.338-342, 2008 Keywords: acibenzolar-S-methyl, jasmonic acid, Agro-Mos, phenylalanine ammonia lyase and peroxidase. exhibited a significant increase in SDW, and did not significantly differ from H and IL. In the potting mix supplemented with nitrogen, all inducers differed from the control treatment regarding to internodal length, whereas only ASM and AM presented a significant difference between one another in the potting mix without the addition of nitrogen. Significant correlations (P=0.05) were found for most of the variables analyzed, with greater correlations observed between SFW and SDW (0.94); IL and H (0.74); SFW and H (0.70); and SDW and H (0.70). ASM induced the leas t amount of PAL acti vity, significantly differing from the remaining treatments. Greater POX activity was observed in ASM, which significantly differed from the control. AM and JA, however, presented lower activity than the control with regard to these enzymes, and it was not possible to confirm induction resistance in these two treatments.Palavras-chave adicionais: acibenzolar-S-metil, ácido jasmônico, Agro-Mós ® , fenilalanina amônia liase e peroxidase.A indução de resistência pelo uso de indutores químicos tem resultado algumas vezes em custo fisiológico para a planta. A resistência induzida em algodoeiro foi avaliada quanto ao custo fisiológico em uma linhagem suscetível a Colletotrichum gossypii var. cephalosporioides (CNPA GO 2002 -7997) que foi cultivada em substratos com dois níveis de nitrogênio e receberam duas a p l i c a ç õ e s d o s i n d u t or e s a c i b e n z o l a r -S -m e t i l ( AS M ) , á c i d o jasmônico (AJ) e Agro-Mós® (AM). As ...

Effect of methyl jasmonate (MeJA)‐induced defenses in rice against the rice leaffolder Cnaphalocrocis medinalis (Guenèe) (Lepidoptera: Pyralidae)

“…The only other instance in past research about the consequences of feeding insects MeJA‐treated plants was reported by Bodnaryk and Rymerson . Jasmonic acid and its active metabolites have been shown to stimulate resistance to various insects, many of which can use many crop plants as hosts: rice, cotton, wheat, tobacco, celery, tomato, soybean, and potato . The broad taxa of insect pests includes the caterpillars (Lepidoptera), beetles (Coleoptera), thrips (Thysanoptera), spider mites (Acari), leafhoppers/planthoppers (Hemiptera), mirid bugs (Heteroptera) and fungal gnats (Diptera) …”

Comparative study of the application of jasmonic acid and pesticide in chilli: effects on physiological activities, yield and viruses control

“…Some previous studies have also examined the effects of jasmonic acid shown in induce resistance against various insects in soybean (CREELMAN et al, 1992), tomato (THALER, 1999), celery (BLACK et al, 2003), tobacco (von DAHL;BALDWIN, 2004), wheat (JAYARAJ et al, 2004), cotton (BARBOSA et al, 2008) and potato (IL'INSKAYA1 et al, 2000).…”

Activation of Systemic Resistance to Magnaporthe oryzae in Rice by Substances Produced by Fusarium solani Isolated from Soil

“…Because the activation of resistance has emerged as an important alternative in the control of fungal plant pathogens (Barbosa et al. ), and micro‐organisms are a possible source of potentially novel resistance‐activating compounds (Lyon and Newton ), a project was initiated to screen soil micro‐organisms for the ability to produce rice blast resistance‐inducing substances. Vegetable tissues are rich in the nutrients required for the growth and production of antimicrobial compounds in the soil (Gamliel et al.…”

“…However, most cultivars lose their resistance within a few years of their release due to the appearance of new races of the pathogen, causing yield instability in several ricegrowing areas throughout the world (Kiyosawa 1982;Ou 1985;Khush and Jena 2009). Because the activation of resistance has emerged as an important alternative in the control of fungal plant pathogens (Barbosa et al 2008), and micro-organisms are a possible source of potentially novel resistance-activating compounds (Lyon and Newton 1999), a project was initiated to screen soil micro-organisms for the ability to produce rice blast resistance-inducing substances. Vegetable tissues are rich in the nutrients required for the growth and production of antimicrobial compounds in the soil (Gamliel et al 2000;Ko et al 2010).…”