Limited effects of xylem anatomy on embolism resistance in cycad leaves.

Autor: Jiang GF; Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, and State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning, Guangxi, 530004, China., Qin BT; Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, and State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning, Guangxi, 530004, China., Pang YK; Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, and State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning, Guangxi, 530004, China., Qin LL; Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, and State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning, Guangxi, 530004, China.; College of Chemistry and Bioengineering, Hechi University, Yizhou, Guangxi, 546300, China., Pereira L; Institute of Botany, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany., Roddy AB; Department of Biological Sciences, Institute of Environment, Florida International University, Miami, FL, 33199, USA.
Jazyk: angličtina
Zdroj: The New phytologist [New Phytol] 2024 Aug; Vol. 243 (4), pp. 1329-1346. Date of Electronic Publication: 2024 Jun 19.
DOI: 10.1111/nph.19914
Abstrakt: Drought-induced xylem embolism is a primary cause of plant mortality. Although c. 70% of cycads are threatened by extinction and extant cycads diversified during a period of increasing aridification, the vulnerability of cycads to embolism spread has been overlooked. We quantified the vulnerability to drought-induced embolism, pressure-volume curves, in situ water potentials, and a suite of xylem anatomical traits of leaf pinnae and rachises for 20 cycad species. We tested whether anatomical traits were linked to hydraulic safety in cycads. Compared with other major vascular plant clades, cycads exhibited similar embolism resistance to angiosperms and pteridophytes but were more vulnerable to embolism than noncycad gymnosperms. All 20 cycads had both tracheids and vessels, the proportions of which were unrelated to embolism resistance. Only vessel pit membrane fraction was positively correlated to embolism resistance, contrary to angiosperms. Water potential at turgor loss was significantly correlated to embolism resistance among cycads. Our results show that cycads exhibit low resistance to xylem embolism and that xylem anatomical traits - particularly vessels - may influence embolism resistance together with tracheids. This study highlights the importance of understanding the mechanisms of drought resistance in evolutionarily unique and threatened lineages like the cycads.
(© 2024 The Authors. New Phytologist © 2024 New Phytologist Foundation.)
Databáze: MEDLINE
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