S11 - Session O5 - Salt tolerance in avocado through physiological and metabolic modifications of the scion and rootstock

Authors: Silit Lazare, Hagai Yasour, Uri Yermiyahu, Yariv Brotman, Alon Ben Gal, Arnon Dag *

Avocado ( Persea americana ) is a highly valuable crop, with rapidly increasing global popularity. Salt stress severely affects the growth and productivity of avocado trees, being one of the most limiting factors for its cultivation through both osmotic and toxic mechanisms. Salt ions penetrate the roots and are then transferred to the foliage. Therefore, understanding the physiological responses of grafted avocado plant organs to salinity is of great interest. During gradual salinity exposure, we compared the ion, metabolite and lipid profiles of leaves, trunks and roots of trees composed of mature 'Hass' scion that was grafted onto two rootstocks of different genetic origins. We found that the rootstock 'VC840' did not restrict the movement of irrigation solution components to the scion, leading to a salt increase in the trunk and leaves. The other rootstock n 'VC152' - functioned selectively, regulating the transport of toxic ions to the scion organs by accumulating them in the roots. The leaves of the scion grafted on the selective rootstock acquired the standard level of necessary minerals without being exposed to excessive salinity. Simultaneously, the carbohydrates and storage lipids produced in the leaves were transferred to the rootstock organs, which became a strong sink. Our study describes mutual scionnrootstock relationships that enable salt tolerance through selective ion transport and metabolic modifications.