Two Evolutionary Diverged Liverworts that Shared the Same Habitats Developed a Few Distinct Seasonal Adaptive Strategies: Insights from a Transcriptomic Approach

Abstract

Since liverworts are among the earliest land plants to undergo seasonal fluctuations, they hold the secret to the molecular mechanism behind seasonal adaptation. Depending on their evolutionary histories, different liverwort species may have relatively distinct adaptive mechanisms. We therefore, performed a seasonal transcriptome analysis of two Indian liverworts, Dumortiera hirsuta and Plagiochasma appendiculatum, during their four different growing seasons (pre-monsoon, monsoon, post-monsoon, and fruiting season). These two species diverged at different points in their evolutionary history but coexist in the same habitat. Phylogenetic trees and evolutionary timescale analyses showed that D. hirsuta is primitive than P. appendiculatum. The RNA-seq analysis showed that D. hirsuta primarily modifies its transcriptome by differentially regulating growth, metabolism, and stress-responsive genes and related TFs in the post-monsoon but mainly induces specific stress-responsive genes in the fruiting season. This is likely to develop reproductive organs in the post-monsoon season and to strategically adapt to the harsh environmental conditions of both seasons by conserving energy during the fruiting season. Conversely, P. appendiculatum exhibited significant transcriptome variability by modulating the expression of genes with similar functions during both the fruiting and post-monsoon seasons, albeit to a lesser degree than D. hirsuta. This suggests that P. appendiculatum strategically modulated its necessary gene expression levels over an extended period of time while taking energy conservation into consideration in order to survive the harsh conditions of both seasons. This study offers the first comprehensive view of seasonal adaptive strategies employed by two evolutionary diverged liverworts that coexist in the same habitat. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.