1. Alternative Oxidase Capacity of Mitochondria in Microsporophylls May Function in Cycad Thermogenesis
- Author
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Tetsuya Hayashi, Yasuko Ito-Inaba, Mizuki Ohata, Kiminori Toyooka, Mitsuhiko P. Sato, Takehito Inaba, Haruna Yamamoto, Yoshitoshi Ogura, Mayuko Sato, and Yuya Kurayama
- Subjects
0106 biological sciences ,education.field_of_study ,Alternative oxidase ,Physiology ,Cellular respiration ,Population ,Plant Science ,Mitochondrion ,Biology ,biology.organism_classification ,01 natural sciences ,Cell biology ,Cycas revoluta ,Genetics ,Microsporangia ,education ,Cycad ,Thermogenesis ,010606 plant biology & botany - Abstract
Cone thermogenesis is a widespread phenomenon in cycads and may function to promote volatile emissions that affect pollinator behavior. Given their large population size and intense and durable heat-producing effects, cycads are important organisms for comprehensive studies of plant thermogenesis. However, knowledge of mitochondrial morphology and function in cone thermogenesis is limited. Therefore, we investigated these mitochondrial properties in the thermogenic cycad species Cycas revoluta Male cones generated heat even in cool weather conditions. Female cones produced heat, but to a lesser extent than male cones. Ultrastructural analyses of the two major tissues of male cones, microsporophylls and microsporangia, revealed the existence of a population of mitochondria with a distinct morphology in the microsporophylls. In these cells, we observed large mitochondria (cross-sectional area of 2 μm2 or more) with a uniform matrix density that occupied >10% of the total mitochondrial volume. Despite the size difference, many nonlarge mitochondria (cross-sectional area
- Published
- 2019