02827naa a2200265 a 450000100080000000500110000800800410001910000170006024501590007726000090023652019950024565300320224065300270227265300230229965300190232265300280234170000150236970000200238470000190240470000260242370000190244970000200246870000220248877300510251011304752020-12-16       2020    bl uuuu     u00u1 u    #d1 aCOSTA, L. C.  aPhosphites of manganese and zinc potentiate the resistance of common bean against infection by Xanthomonas axonopodis pv. phaseoli.h[electronic resource]  c2020  aCommon bacterial blight (CBB), caused by Xanthomonas axonopodis pv. phaseoli var. fuscans (Xapf), negatively impact common bean production globally. Considering the potential of phosphites to protect plants against different diseases, this study investigated the potential of using manganese (Mn) and zinc (Zn) phosphites in common bean for CBB control. Plants were inoculated with Xapf 48 hr after being sprayed with water (control) and solutions (7.5 ml/L) of Mn and Zn phosphites. The area under common bacterial blight progress curve (AUCBBPC) was significantly lower by 34% and 59% for Mn and Zn phosphite treatments in comparison with the control treatment. The AUCBBPC was significantly reduced by 38% for Zn phosphite-sprayed plants compared to Mn phosphite treatment. Phosphite-sprayed plants displayed higher values for area under the curves of net CO2 assimilation rate, stomatal conductance to water vapour, transpiration rate and internal-to-ambient CO2 concentration ratio than non-sprayed plants. This indicates the effect of Mn and Zn phosphites in attenuating the photochemical dysfunctions caused by Xapf infection. Moreover, plants sprayed with Mn phosphite displayed higher values for area under the curves of efficiency in capturing the excitation energy of open reaction centres of PSII and electron transport rate than those non-sprayed indicating their capacity to preserve the capture and the use of the collected energy more efficiently. Lower AUCBBPC for Zn phosphite-sprayed plants resulted in higher concentrations of total chlorophylls. The Zn phosphite-sprayed plants showed higher values for area under the curves of β-1,3-glucanase, phenylalanine ammonia-lyase, polyphenoloxidase, ascorbate peroxidase and superoxide dismutase activities. The Zn phosphite spray primed the plants to enhance their defence response and antioxidant capacity to reduce Xapf-triggered oxidative stress with the preservation of the photosynthetic apparatus more efficiently.  aalternative disease control  ahost defence responses  ainduced resistance  aphotosynthesis  areactive oxygen species1 aDEBONA, D.1 aSILVEIRA, P. R.1 aCACIQUE, I. S.1 aAUCIQUE-PÉREZ, C. E.1 aRESENDE, R. S.1 aOLIVEIRA, J. R.1 aRODRIGUES, F. Á.  tJournal of Phytopathology, USA, p. 1-11, 2020.