Inoue Tomomi, Fujimura Tomoko, Noguchi Ko
National Institute for Environmental Studies, Ibaraki, Japan.
School of Life Science, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan.
Plant Cell Environ. 2025 Feb;48(2):965-977. doi: 10.1111/pce.15184. Epub 2024 Oct 7.
Mangrove plants, which have evolved to inhabit tidal flats, may adjust their physiological and morphological traits to optimize their growth in saline habitats. Furthermore, the confined distribution of mangroves within warm regions suggests that warm temperature is advantageous to their growth in saline environments. We analyzed growth, morphology and respiratory responses to moderate salinity and temperature in a mangrove species, Rhizophora stylosa. The growth of R. stylosa was accelerated in moderate salinity compared with its growth in fresh water. Under warm conditions, the increased growth is accompanied by increased specific leaf area (SLA) and specific root length. Low temperature resulted in a low relative growth rate due to a low leaf area ratio and small SLA, regardless of salinity. Salinity lowered the ratio of the amounts of alternative oxidase to cytochrome c oxidase in the mitochondrial respiratory chain in leaves. Salinity enhanced the leaf respiration rate for maintenance, but under warm conditions this enhancement was compensated by a low leaf respiration rate for growth. In contrast, salinity enhanced overall leaf respiration rates at low temperature. Our results indicate that under moderate saline conditions R. stylosa leaves require warm temperatures to grow with a high rate of resource acquisition without enhancing respiratory cost.
红树林植物已经进化到能够栖息在潮间带，它们可能会调整自身的生理和形态特征，以优化在盐碱栖息地的生长。此外，红树林在温暖地区的有限分布表明，温暖的温度有利于它们在盐碱环境中的生长。我们分析了红树植物红海榄对中度盐度和温度的生长、形态及呼吸响应。与在淡水中的生长相比，红海榄在中度盐度条件下生长加速。在温暖条件下，生长的增加伴随着比叶面积（SLA）和比根长的增加。无论盐度如何，低温都会因叶面积比低和比叶面积小而导致相对生长速率较低。盐度降低了叶片线粒体呼吸链中交替氧化酶与细胞色素c氧化酶的含量比。盐度提高了叶片维持呼吸速率，但在温暖条件下，这种提高被生长所需的低叶片呼吸速率所补偿。相反，盐度在低温下提高了叶片总体呼吸速率。我们的结果表明，在中度盐碱条件下，红海榄叶片需要温暖的温度，以便在不增加呼吸成本的情况下以高资源获取率生长。
