SUGARWIN GENES HAS AN IMPORTANT ROLE IN
SUGARCANE DEFENSE AGAINST OPPORTUNISTIC
PATHOGENS
Franco, FP*1; Medeiros, AH2; Matos, JL1; Castro, PA3; Silva LKS4; Santiago AC4; Silva, FH4; Goldman, GH3;
Moura, DS5; Silva-Filho, MC1.
1Dep. de Genética, Univ. de São Paulo, Piracicaba, SP, 13418-900; 2Dep. de Ciências da Natureza, Matemática e Educação, Univ. Fed. de
São Carlos, Araras, SP, 13600-970; 3Dep. de Ciências Farmacêuticas, Univ. de São Paulo, Ribeirão Preto, SP, 14040-903; 4Dep. de Genética e
Evolução, Univ. Fed. de São Carlos, São Carlos, SP, 13565-905; 5Dep. de Ciências Biológicas Univ. de São Paulo, Piracicaba, SP, 13418-900.
*E-mail: [email protected] keywords: Sugarcane, D. saccharalis, C. falcatum, interaction, plant defense
In sugarcane fields, colonization of the stalk by opportunistic fungi, such as Fusarium verticillioides and Colletotrichum falcatum,
usually occurs after the attack of Diatraea saccharalis caterpillars. Plants respond to insect attack by inducing and accumulating a
large set of defense proteins. SUGARWIN2 (sugarcane wound-inducible protein) is induced in response to mechanical wounding,
D. saccharalis damage, and methyl jasmonate treatment, but not to pathogen infection. The protein itself does not show any
effect on larval development, however, it promotes significant morphological and physiological changes on F. verticillioides and
C. falcatum, by increased vacuolization, points of fractures, leakage of intracellular material, which leads to germlings apoptosis.
We suggest that in the course of evolution, SUGARWIN genes were recruited by sugarcane to protect the plant from fungi that
typically penetrate the plant stalk after insect damage. In this study we analyze the presence of C. falcatum in sugarcane varieties
with different levels of SUGARWIN2 expression. We also evaluate a putative beneficial interaction between the fungi and the
insect. The results suggest that SUGARWIN2 has an important role in plant defense against opportunistic pathogens. The
sugarcane variety that showed higher level of SUGARWIN2 expression had a considerable reduction of C. falcatum contamination.
Furthermore, D. saccharalis seems to create a favorable environment to C. falcatum development through a synergistic interaction,
since the presence of the fungi is highly increased when associated to the larvae. This observation suggests a strong relationship
between D. saccharalis and C. falcatum in sugarcane colonization.
Financial Support: CAPES, CNPq, FAPESP
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