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How Four Plant Species of Australia Respond to Declining Rainfall

Paper Reviewed
D'Agui, H., Fowler, W., Lim, S.L., Enright, N. and He, T. 2016. Phenotypic variation and differentiated gene expression of Australian plants in response to declining rainfall. Royal Society Open Science 3: 160637.

Introducing their intriguing study of an important subject, D'Agui et al. (2016) say that "little is known about the adaptive capacity of species to respond to drying climates, and whether adaptation can keep pace with climate change." And, therefore, they decided to see what they could learn about the subject by examining "the growth of seedlings of four fire-killed species under control and drought conditions for seeds from populations established in years following fire receiving average-to-above-average winter rainfall, or well-below-average winter rainfall." So what did they do? And what did they learn?

This work revealed that the offspring of plants that had established themselves under drought (1) "had more efficient water uptake," and/or (2) "stored more water per unit biomass" or (3) "developed denser leaves," and that (4) "all maintained higher survival in simulated drought than did offspring of plants established in average annual rainfall years." In addition, they report that (5) "seedlings descended from plants established under severe drought also had elevated gene expression in key pathways relating to stress response."

So what do these several experimental findings imply?

D'Agui et al. write that their results demonstrate a capacity for "rapid adaptation to climate change through phenotypic variation and regulation of gene expression," which findings further suggests that "some species and ecosystems might be more resilient to climate change than we currently believe," with "adaptive evolution through natural selection and/or heritable phenotypic plasticity as results of epigenetic processes within a relatively short time frame," which in their case was but a single plant generation.

Posted 10 February 2017