Primary Study Of Promote The Accumulation Of Anti-insect Secondary Metabolites By Copper-inducible Elicitor (CIE) In Cotton

There are three secondary compounds (as gossypol, terpenoid, poly-phenols and flavonoids) to resistance insect damage in cotton, and those secondary compounds can be promoted the accumulation by some biotic (herbivorous insects or other organisms) or abiotic factors (mechanical wound, ultraviolet, environmental stresses, and other abiotic elicitors). In this research, the copper-inducible elicitor (CIE) which is a plant induced-resistance reagent was sprayed on two upland cotton varieties [Xinluzao-17(ZA), Xinluzhong-26(ZH)] foliage during 3-leaf stage and buding stage. And the changes of quantum of gossypol and other terpenoids were measured after induction.The results showed extracting from cotton foliage that the quantum of gossypols and other terpenoids (hemigossypolone, and the heliocides) were significantly higher than control plants. Of these compounds,⑴in 3-leaf stage, gossypol increased by 1.69- and 1.26-fold in ZA3 and ZH3, respectively; heliocides H1 had the largest multiples increase of 1.63-fold and 5.41-fold in ZA3 and ZH3 respectively; heliocides H4 and hemigossypolone increased by 3.87 and 3.41-fold in ZA3, respectively.⑵during buding stage, gossypol had the largest multiples increase of 2.48- and 3.24-fold in ZA and ZH, respectively; heliocides H1 increased by 4.20 and 1.52-fold in ZAL and ZHL, respectively; heliocides H3 and hemigossypolone increased by 1.64- and 1.27-fold in ZHL, respectively. And⑶the quantum of gossypol during buding stage were higher than 3-leaf stage in two varieties by using CIE.The results also showed that the changes of phenylalanine ammonia-lyase (PAL) activities were detected in cotton leaves. The results showed that⑴the PAL activities showed significantly higher than control in two cotton varieties during 3-leaf stage (4.7-fold in ZA and 2.8-fold in ZH) and buding stage (22.8-fold in ZA and 18.4-fold in ZH), arisen the next day and fallen off the tenth day after treated with by CIE;⑵during buding stage, after treated by using CIE, the PAL activities were significantly higher than the 3-leaf stage, and longer than the 3-leaf stage in high activities of duration in two varieties;⑶it may enhance the activity of PAL by using CIE at any cotton growth stages;⑷there may exist a differences of the activity of PAL in different cotton varieties and different growth stages after treated by CIE.that the quantum of gossypol and the activity of PAL can be increased by CIE. Finally, we discuss how CIE may be used in the Integrated Pest Management (IPM) system for cotton resistance control. CIE may be an effective elicitor to promote the accumulation of anti-insect secondary metabolites.