Abstract
Resistance to Erysiphe graminis f. sp. hordei conditioned by the ml- o gene in barley was inhibited with treatments that were expected to lower the concentration of cytoplasmic, ionized calcium in the host cells. When partially dissected coleoptiles were incubated on 10 m m Ca(NO 3) 2 or CaCl 2, resistance was very high, whereas lowering the exogenous calcium concentration to c. 0.25 m m decreased resistance by 50%. Adding indoleacetic acid to the low levels of calcium enhanced this effect, and resistance was almost totally inhibited. Treatments with the calcium ion chelators, chlortetracycline and anhydrochlortetracycline, also inhibited resistance, whereas treatment with the nonchelating analogue, isochlortetracycline, did not. This inhibition could be overcome by adding calcium to the tetracycline solution. These results lead us to hypothesize that calcium is required for activation of the resistance mechanism and that the ml- o mutation affects calcium regulation in the cell, resulting in an elevated cytosolic calcium ion level in the resistant isoline.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.