Action potentials in abscisic acid-deficient tomato mutant generated spontaneously and evoked by electrical stimulation

• Published in: Acta physiologiae plantarum Vol. 37; no. 10
• Main Authors: Macedo, F. C. O., Dziubinska, H., Trebacz, K., Oliveira, R. F., Moral, R. A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2015
• Subjects: Agriculture; Biomedical and Life Sciences; Life Sciences; Original Article; Plant Anatomy/Development; Plant Biochemistry; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; ABA; Electrical signal; Action potential; Stress
• ISSN: 0137-5881; 1861-1664
• DOI: 10.1007/s11738-015-1950-4

Action potentials generated spontaneously (SAPs) and evoked by electrical stimulation (APs) in tomato plants ( Solanum lycopersicum L.) cv. Micro-Tom ABA-deficient mutants ( sitiens —MT sit ) and its wild type (MT wt ) were characterized by continuous monitoring of electrical activity for 66 h and by application of an electrical stimulation supplied extracellularly. MT sit generated SAPs which spread along the stem, including petioles and roots with an amplitude of 44.6 ± 4.4 mV, half-time ( t ½) of 33.1 ± 2.9 s and velocity of 5.4 ± 1.0 cm min −1 . Amplitude and velocity were 43 and 108 % higher in MT sit than in MT wt , respectively. The largest number of SAPs was registered in the early morning in both genotypes. MT sit was less responsive to electrical stimuli. The excitation threshold and the refractory period were greater in MT sit than in MT wt . After current application, APs were generated in the MT wt with 21.2 ± 2.4 mV amplitude and propagated with 5.6 ± 0.5 cm min −1 velocity. Lower intensity stimuli did not trigger APs in these plants. In MT sit APs were measured with amplitude of 26.8 ± 4.8 mV and propagated with velocity of 8.5 ± 0.1 cm min −1 .