Contrasting hypoxia tolerance and adaptation in Malus species is linked to differences in stomatal behavior and photosynthesis. Issue 4 (28th September 2012)

• Record Type: Journal Article
• Authors: Bai, Tuanhui; Li, Cuiying; Li, Chao; Liang, Dong; Ma, Fengwang
• Is Part Of: Physiologia plantarum. Volume 147:Issue 4(2013:Apr.)
• Page Start: 514
• Page End: 523
• Publication Date: 2012-09-28
• Subjects: Plant physiology -- Periodicals; 571.2
• DOI: 10.1111/j.1399-3054.2012.01683.x
• Languages: English
• ISSNs: 0031-9317

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>We examined the potential differences in tolerance to hypoxia by two species of apple rootstocks. Stomatal behavior and photosynthesis were compared between <italic>Malus sieversii</italic> and <italic>Malus hupehensis</italic>. Plants were hydroponically grown for 15 days in normoxic or hypoxic nutrient solutions. Those of <italic>M. sieversii</italic> showed much greater sensitivity, with exposure to hypoxia resulting in higher leaf concentrations of abscisic acid (ABA) that prompted stomatal closure. Compared with the control plants of that species, stomatal density was greater in both new and mature leaves under stress conditions. In contrast, stomatal density was significantly decreased in leaves from <italic>M. hupehensis</italic>, while stomatal length was unaffected. Under stress, the net photosynthetic rate, stomatal conductance and chlorophyll contents were markedly reduced in <italic>M. sieversii</italic>. The relatively hypoxia‐tolerant genotype <italic>M. hupehensis</italic>, however, showed only minor changes in net photosynthesis or chlorophyll content, and only a slight decrease in stomatal conductance due to such treatment. Therefore, we conclude that the more tolerant <italic>M. hupehensis</italic> utilizes a better protective mechanism for retaining higher photosynthetic capacity than does the hypoxia‐sensitive <italic>M. sieversii</italic>. Moreover, this contrast in tolerance and adaptation to stress is linked to differences in their stomatal behavior, photosynthetic capacity and possibly their patterns of native distribution.</p> </abstract>