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bioRxiv · 10.1101/001032

Mechanism of β-Aminobutyric Acid-Induced Resistance in Wheat to the Grain Aphid, Sitobion avenae

Abstract

The non-protein amino acid {beta}-aminobutyric acid (BABA) could induce plant resistance to a broad spectrum of biotic and abiotic stresses. However, BABA-induced plant resistance to insects is less well-studied, especially its underlying mechanism. In this research, we applied BABA to wheat seedlings and tested its effects on Sitobion avenae. When applied as a soil drench, BABA significantly reduced weight of S. avenae, whereas foliar spray and seed treatment had no such effects. BABA-mediated suppression of S. avenae growth is dose dependent and could last at least for 7 days. The aminobutyric acid concentration in phloem sap of BABA-treated plants accumulated to high levels and increased with BABA concentrations applied. Moreover, after 10 days of treatment, the aminobutyric acid content in BABA-treated plants was still higher than that in control treatment. S. avenae could not discriminate artificial diet containing BABA from standard diet, indicating that BABA itself is not a deterrent to this aphid. Also S. avenae did not show preference for control plants or BABA-treated plants. Consistent with choice test results, S. avenae had similar feeding activities on control and BABA-treated plants, suggesting that BABA did not induce antifeedants in wheat seedlings. In addition, aminobutyric acid concentration in S. avenae feeding on BABA-treated plants was significantly higher than those feeding on control palnts. S. avenae growth rate was reduced on artificial diet containing BABA, indicating direct toxic effects of BABA to this aphid. These results suggest that BABA application could enhance wheat plant resistance to S. avenae and the mechanism is possibly due to direct toxicity of high BABA contents in plant phloem.

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He-He Cao, Meng Zhang, Hui Zhao, Yi Zhang, Xing-Xing Wang, Shan-Shan Guo, Zhan-Feng Zhang, Tong-Xian Liu. 2013-12-02. Mechanism of β-Aminobutyric Acid-Induced Resistance in Wheat to the Grain Aphid, Sitobion avenae. https://doi.org/10.1101/001032

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