Zhigang Xue, Shangyong Yin, Yuedong Guo, Kejia Cui, Lei Wu, Xingpeng He, Hao Wu, Runmei Gao, Jinhua Bai
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引用次数: 0
Abstract
Introduction: Intensified drought induced by climate change is threatening the natural regeneration of forests, yet coexisting tree species can maintain their survival and regeneration by adopting divergent carbon allocation strategies. This study compared leaf-scale drought responses of Quercus variabilis and Q. mongolica seedlings originating from the ecotone of the Zhongtiao Mountains.
Methods: Multiple indicators were measured under four water regimes: control (CK), light drought (LD), moderate drought (MD), and severe drought (SD), including leaf morphology, photosynthetic and gas exchange parameters, hydraulic traits, carbon storage traits, stress defense traits, and nutrient stoichiometry. Principal component analysis (PCA) and structural equation modeling (SEM) were used to evaluate interspecific differences in drought adaptation strategies.
Results: Drought suppressed leaf growth and gas exchange, lowered leaf water potential and relative water content, aggravated damage to hydraulic function, and boosted biochemical responses associated with stress defense in both species. For Q. variabilis, leaf non-structural carbohydrate (NSC) concentrations were tightly correlated with growth-related traits, indicating that NSCs play a vital role in sustaining growth and accumulating carbon after growth limitation, reflecting a growth-prioritized resource allocation strategy. In contrast, leaf NSCs of Q. mongolica seedlings exhibited stronger coordinated covariation with stomatal behavior and antioxidant defenses, suggesting that this species prioritizes defense maintenance and physiological stability under drought stress, representing a defense-prioritized resource allocation strategy.
Discussion: Seedlings of Q. variabilis and Q. mongolica adopt growth-prioritized and defense-prioritized adaptation strategies under drought, respectively. Such physiological divergence serves as a physiological foundation for niche differentiation, divergent regeneration patterns, and coexistence of seedlings of the two Quercus species within the ecotone.
期刊介绍：
In an ever changing world, plant science is of the utmost importance for securing the future well-being of humankind. Plants provide oxygen, food, feed, fibers, and building materials. In addition, they are a diverse source of industrial and pharmaceutical chemicals. Plants are centrally important to the health of ecosystems, and their understanding is critical for learning how to manage and maintain a sustainable biosphere. Plant science is extremely interdisciplinary, reaching from agricultural science to paleobotany, and molecular physiology to ecology. It uses the latest developments in computer science, optics, molecular biology and genomics to address challenges in model systems, agricultural crops, and ecosystems. Plant science research inquires into the form, function, development, diversity, reproduction, evolution and uses of both higher and lower plants and their interactions with other organisms throughout the biosphere. Frontiers in Plant Science welcomes outstanding contributions in any field of plant science from basic to applied research, from organismal to molecular studies, from single plant analysis to studies of populations and whole ecosystems, and from molecular to biophysical to computational approaches.
Frontiers in Plant Science publishes articles on the most outstanding discoveries across a wide research spectrum of Plant Science. The mission of Frontiers in Plant Science is to bring all relevant Plant Science areas together on a single platform.
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