Phylogenetic analysis of basal land plants based on developmental genes of antheridium and archegonium

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K06376
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 45030:Biodiversity and systematics-related
• Research Institution: Kanazawa University
• Principal Investigator: Kofuji Rumiko 金沢大学, 生命理工学系, 助教 (40324066)
• Co-Investigator(Kenkyū-buntansha): 山田 敏弘 大阪市立大学, 大学院理学研究科, 教授 (70392537)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: コケ植物 / 造精器 / 造卵器 / 生殖発生 / 遺伝子発現 / ツノゴケ / 系統

Outline of Final Research Achievements

To compare the developmental genes for antheridium and archegonium in all basal groups of land plants, we observed their developmental process in detail in hornworts and then performed a comprehensive search for gene expression. Recently, hornworts have been shown to be a basal group of bryophytes, and a model strain has been established. We found the developmental process of the antheridium chamber which overturned the textbook's description and found similarities in the early developmental process of both gametangia.About half of the genes specifically expressed in the archegonium meristem of hornworts had no ortholog in liverwort, Physcomitrium patens, and Arabidopsis thaliana. We obtained candidate genes commonly expressed in the reproductive organs of all three bryophyte groups, one of which was unique to bryophytes.

Free Research Field

植物の発生進化学

Academic Significance and Societal Importance of the Research Achievements

本研究で明らかにした造精器の発生過程は、これまで50年以上も信じられていた教科書的事実を覆すものであり、教科書の記述を書き換えるとともに、ツノゴケ類の形態及び発生過程の再検討を促すものである。この発見により、これまでシダ植物の基部系統群の発生と比較されることもあった発生過程がツノゴケには存在しないことがわかった。また造精器と造卵器の初期発生過程の類似性は、両者の発生で同じメカニズムが使われている可能性を示している。