Plant Diversity ›› 2021, Vol. 43 ›› Issue (04): 324-330.DOI: 10.1016/j.pld.2020.11.007

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Cavitation resistance of peduncle, petiole and stem is correlated with bordered pit dimensions in Magnolia grandiflora

Feng-Ping Zhanga,b,c, Jiao-Lin Zhanga, Timothy J. Brodribbd, Hong Huc   

  1. a CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, Yunnan, China;
    b College of Traditional Chinese Medicine, Yunnan Key Laboratory of Dai and Yi Medicines, Yunnan University of Chinese Medicine, Kunming, 650500, Yunnan, China;
    c Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Yunnan Key Laboratory for Wild Plant Resources, Kunming 650201, Yunnan, China;
    d School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia
  • Received:2020-07-05 Revised:2020-11-04 Online:2021-08-25 Published:2021-09-07
  • Contact: Jiao-Lin Zhang
  • Supported by:
    We thank Rong-Fei Chen and Jing-Qiu Feng for assistance with measurements of anatomical traits and water potentials. We thank Zhi-Jia Gu for providing technical support with electron microscopy. This study was supported by the National Natural Science Foundation of China (31670415, 31870385, 31960224), the "Young Top Talents" Ten Thousands Plan in Yunnan Province (YNWR-QNBJ-2018-337), Science research of Yunnan Provincial Department of Education (2019J1068) and open funding from the CAS Key Laboratory of Tropical Forest Ecology to F.P. Zhang.

Abstract: Variation in resistance of xylem to embolism among flowers, leaves, and stems strongly influences the survival and reproduction of plants. However, little is known about the vulnerability to xylem embolism under drought stress and their relationships to the anatomical traits of pits among reproductive and vegetative organs. In this study, we investigated the variation in xylem vulnerability to embolism in peduncles, petioles, and stems in a woody plant, Magnolia grandiflora. We analyzed the relationships between water potentials that induced 50% embolism (P50) in peduncles, petioles, and stems and the conduit pit traits hypothesized to influence cavitation resistance. We found that peduncles were more vulnerable to cavitation than petioles and stems, supporting the hypothesis of hydraulic vulnerability segmentation that leaves and stems are prioritized over flowers during drought stress. Moreover, P50 was significantly correlated with variation in the dimensions of inter-vessel pit apertures among peduncles, petioles and stems. These findings highlight that measuring xylem vulnerability to embolism in reproductive organs is essential for understanding the effect of drought on plant reproductive success and mortality under drought stress.

Key words: Drought, Flower, Pit traits, Xylem embolism, Magnolia