Assessment of photosynthetic performance, carboxylase activities, and ATP content during tetrasporic development in Gracilariopsis lemaneiformis (Gracilariaceae, Rhodophyta)

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• 作者：Jinguo Wang ; Zhenghong Sui ; Yiyi Hu ; Wei Zhou ; Huihui Wei…
• 关键词：Adenosine ; 5′-triphosphate ; Gracilariopsis lemaneiformis ; Rhodophyta ; Phosphoenolpyruvate carboxylase ; Photosystem II ; Ribulose ; 1 ; 5 ; bisphosphate carboxylase ; Tetraspore
• 刊名：Journal of Applied Phycology
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：28
• 期：5
• 页码：2939-2952
• 全文大小：834 KB
• 刊物主题：Plant Sciences; Freshwater & Marine Ecology; Plant Physiology; Ecology;
• 出版者：Springer Netherlands
• ISSN：1573-5176
• 卷排序：28

文摘

In this study, the development of Gracilariopsis lemaneiformis tetrasporophytes during tetraspore formation and release was investigated with the aim to understand the physiological and biochemical bases during tetraspore formation and release especially from energy metabolism, contributing to elucidation of the control of fertility, and to discover indicators related to the fertility level. The accompanied changes in photosystem II (PSII) photosynthetic abilities, adenosine-5′-triphosphate (ATP) content, ribulose-1,5-bisphosphate carboxylase (Rubisco), and phosphoenolpyruvate carboxylase (PEPC) activities of three strains of G. lemaneiformis, the wild type, cultivar 981, and ZC, cultivated in the laboratory and collected from the field were measured. Light microscopy observations showed that the differentiation process for all tetrasporophytes could be divided into four phases. Cultivar 981 produced the least number of tetrasporangia and tetraspores, which confirmed the low fertility of this strain. The photosynthetic activity, measured by effective PSII quantum yield (Y(II)) showed, fell earlier and rose later, and the values in phase IV were the highest for all three strains during the development of tetrasporophytes. ATP content decreased as developmental process progressed, suggesting that the thalli utilized more substrate and energy in order to heal wounds caused by spore release in phases III and IV. Moreover, the variations in Rubisco activity had the similar trend as ATP content and the same pattern as the Y(II) values during tetrasporic development. PEPC activities were approximately 1 to 2 orders of magnitude higher than those of Rubisco during the development process in the laboratory and field samples, which suggested that an anaplerotic reaction of G. lemaneiformis is substantial because of high growth rates in phase I and high demand for organic and amino acids for the synthesis of major cell components such as proteins in phases II, III, and IV. The results also suggested that the fertility of G. lemaneiformis tetrasporophytes, coupled with the variation in photosynthetic and carboxylase activities, and its increased energy use would be useful characteristics when attempting to breed new strains of G. lemaneiformis.