Abscisic acid acts essentially on stomata, not on the xylem, to improve drought resistance in tomato.

Autor: Haverroth EJ; Department of Crop and Soil Sciences, North Carolina State University, Raleigh, North Carolina, USA.; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil., Oliveira LA; Department of Crop and Soil Sciences, North Carolina State University, Raleigh, North Carolina, USA.; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil., Andrade MT; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil., Taggart M; Department of Crop and Soil Sciences, North Carolina State University, Raleigh, North Carolina, USA., McAdam SAM; Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, USA., Zsögön A; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil., Thompson AJ; Centre for Soil, Agrifood and Biosciences, Cranfield University, Bedfordshire, UK., Martins SCV; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil., Cardoso AA; Department of Crop and Soil Sciences, North Carolina State University, Raleigh, North Carolina, USA.
Jazyk: angličtina
Zdroj: Plant, cell & environment [Plant Cell Environ] 2023 Nov; Vol. 46 (11), pp. 3229-3241. Date of Electronic Publication: 2023 Aug 01.
DOI: 10.1111/pce.14676
Abstrakt: Drought resistance is essential for plant production under water-limiting environments. Abscisic acid (ABA) plays a critical role in stomata but its impact on hydraulic function beyond the stomata is far less studied. We selected genotypes differing in their ability to accumulate ABA to investigate its role in drought-induced dysfunction. All genotypes exhibited similar leaf and stem embolism resistance regardless of differences in ABA levels. Their leaf hydraulic resistance was also similar. Differences were only observed between the two extreme genotypes: sitiens (sit; a strong ABA-deficient mutant) and sp12 (a transgenic line that constitutively overaccumulates ABA), where the water potential inducing 50% embolism was 0.25 MPa lower in sp12 than in sit. Maximum stomatal and minimum leaf conductances were considerably lower in plants with higher ABA (wild type [WT] and sp12) than in ABA-deficient mutants. Variations in gas exchange across genotypes were associated with ABA levels and differences in stomatal density and size. The lower water loss in plants with higher ABA meant that lethal water potentials associated with embolism occurred later during drought in sp12 plants, followed by WT, and then by the ABA-deficient mutants. Therefore, the primary pathway by which ABA enhances drought resistance is via declines in water loss, which delays dehydration and hydraulic dysfunction.
(© 2023 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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