News Release

How plants conquered land

Peer-Reviewed Publication

Proceedings of the National Academy of Sciences

Green plants adapted to land through the evolution of an ancestral signaling pathway that enabled rapid response to drought stress, a study finds. The movement of green plants to land at least 450 million years ago represents one of the most important steps in the evolution of life on Earth. Douglas Soltis, Barry Pogson, Zhong-Hua Chen, and colleagues reveal that unique genetic features of desiccation sensing and protection in streptophyte algae - the algal ancestors of land plants - represent crucial evolutionary factors that may have facilitated the colonization and subsequent diversification of terrestrial habitats. The authors conducted comparative genetic similarity analysis of predicted sequences from 61 protein families from 31 species representing the major clades of land plants and algae. The results revealed that a molecular mechanism known as SAL1-PAP chloroplast retrograde signaling evolved in streptophyte algae and is broadly conserved across diverse land plant lineages. Moreover, experimental evidence suggested that the evolution of this pathway enabled early land plants to sense drought and protect vital photosynthetic tissue by triggering the closure of stomata, which are pores that regulate gas exchange and hydration. Taken together, the findings suggest that the sensing and signaling networks that land plants use to adapt to variable and harsh terrestrial environments existed in their algal ancestors, according to the authors.

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Article #18-12092: "Evolution of chloroplast retrograde signaling facilitates green plant adaptation to land," by Chenchen Zhao et al.

MEDIA CONTACTS: Doug Soltis, University of Florida, Gainesville, FL; tel: 352-273-1963; e-mail: <dsoltis@ufl.edu>; Barry Pogson, The Australian National University, Acton, AUSTRALIA; tel: +61-2-6125-5629; e-mail: <barry.pogson@anu.edu.au>; Zhong-Hua Chen, Western Sydney University, Penrith, AUSTRALIA; tel: +61-2-4570-1934, +61 466544696; e-mail: <z.chen@westernsydney.edu.au>


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