AUTHOR=Qin Shanshan , Tang Yuehui , Chen Yaping , Wu Pingzhi , Li Meiru , Wu Guojiang , Jiang Huawu 

TITLE=Overexpression of the Starch Phosphorylase-Like Gene (PHO3) in Lotus japonicus has a Profound Effect on the Growth of Plants and Reduction of Transitory Starch Accumulation

JOURNAL=Frontiers in Plant Science

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2016.01315

DOI=10.3389/fpls.2016.01315

ISSN=1664-462X

ABSTRACT=<p>Two isoforms of starch phosphorylase (PHO; EC 2.4.1.1), plastidic PHO1 and cytosolic PHO2, have been found in all plants studied to date. Another starch phosphorylase-like gene, <italic>PHO3</italic>, which is an ortholog of <italic>Chlamydomonas PHOB</italic>, has been detected in some plant lineages. In this study, we identified three PHO isoform (<italic>LjPHO</italic>) genes in the <italic>Lotus japonicus</italic> genome. Expression of the <italic>LjPHO3</italic> gene was observed in all tissues tested in <italic>L. japonicus</italic>, and the LjPHO3 protein was located in the chloroplast. Overexpression of <italic>LjPHO3</italic> in <italic>L. japonicus</italic> resulted in a drastic decline in starch granule sizes and starch content in leaves. The <italic>LjPHO3</italic> overexpression transgenic seedlings were smaller, and showed decreased pollen fertility and seed set rate. Our results suggest that <italic>LjPHO3</italic> may participate in transitory starch metabolism in <italic>L. japonicus</italic> leaves, but its catalytic properties remain to be studied.</p>