[植物演化] 演化上最接近陸生植物的藻類基因體解碼。 20191116 Cell

Plasmodesmata
Nov 16, 2019
2 min read

Genomes of Subaerial Zygnematophyceae Provide Insights into Land Plant Evolution

Shifeng Cheng, Wenfei Xian, Yuan Fu, Birger Marin, Jean Keller, Tian Wu, Wenjing Sun, Xiuli Li, Yan Xu, Yu Zhang, Sebastian Wittek, Tanja Reder, Gerd Günther, Andrey Gontcharov, Sibo Wang, Linzhou Li, Xin Liu, Jian Wang, Huanming Yang, Xun Xu, Pierre-Marc Delaux, Barbara Melkonian, Gane Ka-Shu Wong, and Michael Melkonian

Summary

The transition to a terrestrial environment, termed terrestrialization, is generally regarded as a pivotal event in the evolution and diversification of the land plant flora that changed the surface of our planet. Through phylogenomic studies, a group of streptophyte algae, the Zygnematophyceae, have recently been recognized as the likely sister group to land plants (embryophytes). Here, we report genome sequences and analyses of two early diverging Zygnematophyceae (Spirogloea muscicola gen. nov. and Mesotaenium endlicherianum) that share the same subaerial/terrestrial habitat with the earliest-diverging embryophytes, the bryophytes.We provide evidence that genes (i.e., GRAS and PYR/PYL/RCAR) that increase resistance to biotic and abiotic stresses in land plants, in particular desiccation, originated or expanded in the common ancestor of Zygnematophyceae and embryophytes, and were gained by horizontal gene transfer (HGT) from soil bacteria. These two Zygnematophyceae genomes represent a cornerstone for future studies to understand the underlying molecular mechanism and process of plant terrestrialization.

生長於靠近水面的鏈形藻類的基因體資訊，提供了植物演化成陸地植物的可能資訊

總結

”陸地化“是指植物從在水中生活轉成在陸地上生長的過程，一般認為是陸生植物演化以及分化上關鍵的一個事件，最終使得陸生開花植物改變了地球的表面樣貌。經由遺傳演化的研究，一群鏈形藻類（Zygnematophyceae）在近代被認為是陸生植物（embryophytes）的姊妹群植物。在此，我們報導並分析了了兩種早期分化出來的鏈形植物（Spirogloea muscicola gen. nov. and Mesotaenium endlicherianum）的基因體。這兩種鏈形植物與早期演化出來的陸生植物有相似的水陸生棲息地。我們提供了一些關於在陸生植物中，可以增加生物性與非生物性壓力，尤其是對抗缺水狀態的基因（GRAS以及PYR/PYL/RCAR）是在鏈形藻類與陸生植物的共同祖先中，從土壤細菌中經由水平基因轉移而演化出現並且擴張。這兩種鏈形藻類的基因體，建立了未來研究並瞭解植物陸地化背後機制研究的基石。