Identification of factors that cause heterophylly in Ludwigia arcuata Walt. (Onagraceae)
Identification of factors that cause heterophylly in Ludwigia arcuata Walt. (Onagraceae)
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DOI：
10.1055/s-2001-11748
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发表时间：
2001-01-01
期刊：
影响因子：
3.9
通讯作者：
Nagata, T
中科院分区：
文献类型：
--
作者：
Kuwabara, A;Tsukaya, H;Nagata, T
Ludwigia aluminata的沉水叶比陆生叶窄得多。这种异型叶变化在其它水生被子植物如异叶水马齿、马缨丹和扇叶毛茛中也有观察到，但对毛茛异型叶形成的原因进行了探讨。但看起来很不一样。与其它表皮细胞形状发生变化的物种相比，L.结果发现，在横切面上排列的表皮细胞数量的变化是导致表皮细胞数量减少的原因。叶片对水面以上和水面以下形状变化的敏感性取决于发育阶段：比第四叶年轻的叶片对环境变化做出反应，而比第五叶老的叶片则没有。ACC（1-aminocyclopropane-1-carboxylic acid），乙烯的前体处理，诱导形成的淹没型叶片上的地面芽，这意味着乙烯可能是内源因子负责叶片形状的变化。并对植物适应环境变化的意义进行了讨论。
The submerged leaves of Ludwigia arcuata are much narrower than the terrestrial leaves. Such heterophyllous changes in leaf shape have been observed in other aquatic angiosperms, such as Callitriche heterophylla, Hippuris vulgaris and Ranunculus flabellaris, but the cause of the formation of heterophyllous leaves in L. arcuata seems to be quite different. In contrast to other species, in which the shapes of epidermal cells have been changed, the change of leaf shape in L. arcuata was found to be due to changes in the numbers of epidermal cells aligned in transverse sections. The susceptibility of leaves to changes in shape above and below the water is dependent on the developmental stages: leaves younger than the fourth leaf responded to a change in environment, while leaves older than the fifth leaf did not. Treatment with ACC (1-aminocyclopropane-1-carboxylic acid), a precursor to ethylene, induced the formation of submerged-type leaves on terrestrial shoots, implying that ethylene might be the endogenous factor responsible for the change in leaf shape. The results are discussed with reference to the significance acclimation plants to environmental changes.