Chinese Journal of Nature ›› 2021, Vol. 43 ›› Issue (3): 225-231.doi: 10.3969/j.issn.0253-9608.2021.03.008

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Overview on the origin of land plants

WU Zhen, CHENG Shifeng   

  1. Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120,China
  • Received:2021-04-10 Online:2021-06-25 Published:2021-06-13

Abstract: The transition of the algal ancestor of land plants from fresh water to land is important in the study of plant evolutionary biology, which has also changed the terrestrial ecosystem of the earth but the evolutionary mechanism of plant terrestrialization remains unknown. The recent report of high-quality reference genomes of several streptophyte algae and one hornwort sheds light on this major event. Based on these studies, we can draw the following conclusions: ①Zygnematophyceae was found to be the closest sister group to the common ancestor of land plants found so far; ②The acquisition of GRAS and PYL genes from soil bacteria via horizontal gene transfer plays an important role in driving the adaptive process of plant terrestrialization; ③The terrestrialization of plant ancestors is an asymptotic evolutionary process, and the genetic material has gone through a series of pre-adaptation processes, which many gene families previously thought to be unique to land plants exist in more primitive green algae; ④Genomics is an important method for studying terrestrialization and its reversibility process (such as some aquatic angiosperms). The molecular mechanism of the adaptive process of plant terrestrialization is still one of the current research hotspots, including artificial design of “experimental evolution”, horizontal gene transfer, a natural transgenic engineering event, and its key role in plant evolution and adaptation.