Abstract
The non-protein amino acid β-aminobutyric acid (BABA) can 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 (F.). When applied as a soil drench, BABA significantly reduced weights of S. avenae, whereas foliar spray and seed treatment had no such effects. BABA-mediated suppression of S. avenae growth was dose dependent and lasted at least for 7 days. The aminobutyric acid concentration in phloem sap of BABA-treated plants was higher 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. Sitobion 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 plants. Sitobion avenae growth rate was reduced on the artificial diet containing BABA, indicating that BABA had direct toxic effects on this aphid species. These results suggest that BABA application reduced S. avenae performance on wheat seedlings and the mechanism is possibly due to direct toxicity of high BABA contents in plant phloem.
Highlights
The non-protein amino acid b-aminobutyric acid (BABA) can enhance plant resistance against a broad spectrum of phytopathogens
Sitobion avenae performance Compared with the control treatment, BABA applied as a soil drench significantly reduced weights of S. avenae on wheat seedlings and the effects increased with BABA concentration (F = 107.66, df = 5, 24, P,0.001; Fig. 1)
Wheat seedlings that soil-drenched with high concentration (50 mM) BABA had lower fresh shoot weights compared with the control treated-plants (F = 4.476, df = 4, 44, P = 0.004) (Fig. S1)
Summary
The non-protein amino acid b-aminobutyric acid (BABA) can enhance plant resistance against a broad spectrum of phytopathogens. BABA-induced plant resistance is effective against viruses, bacteria, oomycetes, fungi and phytopathogenic nematodes [1,2,3,4]. The mechanism of BABA-induced plant resistance to different pathogens is variable. BABA-induced Arabidopsis resistance against the oomycete pathogen Peronospora parasitica (Pers.) Fr. is based on callose deposition, and independent of jasmonic acid (JA), salicylic acid (SA) and ethylene signaling pathways, whereas against the bacteria Pseudomonas syringae is solely dependent of SA and NPR1 (nonexpressor of pathogenesis-related genes 1) [3]. In addition to conferring plant resistance to pathogens, BABA improves plant tolerance to salt, drought and high temperature, which is associated with accumulation of the abscisic acid [6,7,8]. Arabidopsis mutants that are insensitive to BABA-induced sterility have reduced resistance level to pathogens or tolerance to salt, suggesting that BABA-induced plant resistance to biotic and abiotic stresses has a genetic basis [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
