Diurnal fluctuations of metabolites in leaves of 'Zesy002' kiwifruit

H. Boldingh, T. Pereira, S. Shepherd, K. Hewitt, J. Cooney, D. Rowan, D. Hedderley, D. Jensen, T. Trower, A. Richardson
Metabolite changes are often used to better understand the effects of experimental treatments on the physiological and metabolic processes of horticultural crops. Shade and time of day are both factors that affect the concentrations of metabolites, in particular carbohydrates. In this study we investigated the effect of reduced light on the diurnal cycling of metabolites by application of 50% shade cloth to whole vines of 'Zesy002' kiwifruit over a 28-h period. Diurnal patterns of the metabolites were also measured for a 32-h period, starting 5 h prior to the application of the shade cloth. The effects of shading on the photosynthetic rate, starch, total soluble carbohydrate and phytohormones were determined in the youngest mature leaves of shaded and non-shaded vines. Non-shaded leaves accumulated more sucrose and salicylic acid than the shaded leaves between sunrise and mid-morning; however, there were no significant differences found in the photosynthetic rate, starch, cytokinins and other stress hormone concentrations between the two treatments over the 24-h period of shading. Photosynthetic rate, starch, total soluble carbohydrates and several stress response and growth regulation phytohormones showed diurnal patterns over the 32-h period. These diurnal fluctuations in the concentration of metabolites need to be considered when sampling tissues for the assessment of metabolite processes in kiwifruit.
Boldingh, H., Pereira, T., Shepherd, S., Hewitt, K., Cooney, J., Rowan, D., Hedderley, D., Jensen, D., Trower, T. and Richardson, A. (2022). Diurnal fluctuations of metabolites in leaves of 'Zesy002' kiwifruit. Acta Hortic. 1332, 155-162
DOI: 10.17660/ActaHortic.2022.1332.21
carbohydrate, phytohormone, shading, kiwifruit

Acta Horticulturae