Leaf to Root Morphological and Anatomical Indicators of Drought Resistance in Coffea canephora After Two Stress Cycles

Coffea canephora genotypes adopt distinct strategies to cope with drought and rehydration. We hypothesized that the greater drought tolerance of genotype ‘3V’ compared to ‘A1’, previously reflected in physiological and anatomical leaf traits after two water-stress (WS) cycles, could also be observed in P–V curve responses, root and branch anatomy, leaf midrib elongation (CVL), and root distribution. The ‘3V’ and ‘A1’ plants were grown under well-watered (WW) conditions and two cycles of water stress (WS). The ‘3V’ was more sensitive to WS, with reduced branch xylem vessel density (BXVD), while ‘A1’ demonstrated increased BXVD. Root xylem vessel area (RXVA) decreased to a greater extent in ‘3V’ than in ‘A1’, and both genotypes showed increased bulk elastic modulus. Regardless of water conditions, ‘A1’ maintained a higher relative leaf water content at the turgor loss point (RWCTLP). Morphological acclimation did not occur in the second WS cycle. The ‘3V’ plants developed greater root mass in deeper soil layers than ‘A1’ under the WS condition. These findings suggest that ‘A1’ follows a conservative drought-avoidance strategy with lower physio-morphological plasticity, while ‘3V’ exhibits greater drought tolerance. Such responses highlighted coordinated physiological, morphological, and anatomical adaptations of the above- and below-ground organs for resource acquisition and conservation under WS.

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Funding Information: This research was funded by Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ, Brazil) granted to E.C. (200.957/2022), together with fellowships awarded to M.R., D.F.B., and W.P.B. (204.636/2024, E–26/200.327/2020, and E–26/200.172/2021). The research was additionally funded by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brazil) with fellowships granted to G.A.R.d.S., C.M.A., A.R.S., L.C.S.B., L.F.T.B. and L.C.Z. (88887.968322/2024–00, 88887.903335/2023–00, 88887.993832/2024-00, 88887.991771/2024-00, 88887.822657/2023–00, and 88887.991759/2024-00), and National Council for Scientific and Technological Development (CNPq, Brazil) by fellowship awarded to E.C. (304470/2023–6). The research was additionally funded by Fundação para a Ciência e a Tecnologia, I.P. (FCT), Portugal, through the projects UIDB/00239: Centro de Estudos Florestais (https://doi.org/10.54499/UIDB/00239/2020), and UIDP/04035/2020: Unidade de Geobiociências, Geoengenharias e Geotecnologias (https://doi.org/10.54499/UIDB/04035/2020), as well as through the Associate Laboratory TERRA (LA/P/0092/2020, https://doi.org/10.54499/LA/P/0092/2020) granted to J.C.R. Publisher Copyright: © 2025 by the authors.