Inherent and stress-induced responses of fine root morphology and anatomy in commercial grapevine rootstocks with contrasting drought resistance

Authors: REINGWIRTZ, IDAN - University Of California, Davis; URETSKY, JAKE - University Of California, Davis; CUNEO, ITALO - Pontifical Catholic University Of Valparaiso; KNIPFER, THORSTEN - University Of British Columbia; REYES, CLARISSA - University Of California, Davis; WALKER, ANDREW - University Of California, Davis; McElrone, Andrew

Submitted to: Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/24/2021
Publication Date: 6/1/2021
Citation: Reingwirtz, I., Uretsky, J., Cuneo, I.F., Knipfer, T.M., Reyes, C., Walker, A.M., McElrone, A.J. 2021. Inherent and stress-induced responses of fine root morphology and anatomy in commercial grapevine rootstocks with contrasting drought resistance. Plants. 10(6). Article 1121. https://doi.org/10.3390/plants10061121.
DOI: https://doi.org/10.3390/plants10061121

Interpretive Summary:

Technical Abstract: Some grapevine rootstocks perform better than others during and after drought events, yet it is not clearly understood how inherent and stress-induced differences in root morphology and anatomy along the length of fine roots are involved in these responses. Using a variety of growing conditions and plant materials, we observed significant differences in root diameter, specific root length (SRL) and root diameter distribution between the two commonly used commercial grapevine rootstocks: Richter 110R (110R; drought resistant) and Millardet et de Grasset 101-14 (101-14Mgt; drought sensitive). 110R consistently showed greater root diameters with lower SRL and proportion of root length comprised of fine lateral roots. 110R also exhibited significantly greater distance from tip to nearest lateral, higher white root length, and higher proportion of root length that is white under drought stress. Our morphological results suggest that drought resistance in grapevine rootstocks is associated with thick, limitedly-branched roots with a larger proportion of white-functional roots that likely favors continued resource acquisition at depth. Our analysis of cortical lacunae mapping showed similar patterns between the rootstocks, where mechanical failure of cortical cell was common in the maturation zone, limited near the root tip, and increased with drought stress for both genotypes. A common parent species for these rootstocks may drive the consistent lacunae formation in developmentally advanced roots.