New paper in New Phytologist!

This paper has had a long history. Too long. First submitted in 2018 and after several revisions, it was accepted in New Phytologist! This paper investigates how fungal endophyte diversity is shaped by leaf chemical composition. We always suspected that nutrients, like nitrogen, might be negatively correlated with species richness (up to a certain point) since this is the pattern we see in many other taxa - especially plant communities. But we weren't thinking about a possible second class of compounds that could also strongly influence species competition and survival - toxins. In the Jug Handle Pygmy Reserve, plants grow along a series of uplifted marine terraces that have been undergoing weathering for millions of years. Plants growing on the oldest terrace have the least amount of nutrients due to the greatest amount of weathering. As it turns out, they have also accumulated heavy metals. The youngest terrace, even though they have the greatest amount of nitrogen, was also exposed to salt sprays. Plant leaves growing along the coast have incredibly high amounts of sodium. We found a very strong negative correlation between endophyte species richness and nitrogen:phosphorus ratios in two evolutionarily distant species - Pinus muricata and Vaccinium ovatum. And then, surprisingly, we found a positive correlation between endophyte species richness and sodium in both species. Sodium can be toxic to fungi if they can't regulate osmotic potential in their cells. This was a complicated, but serendipitous, discovery for us. We propose that stressed plants can exhibit both low foliar nutrients or high levels of toxic compounds, and that both of these stress responses predict endophyte species richness. Stressful conditions that limit growth of fungi may increase their diversity due to the suppression of otherwise dominating species.

Finally, I'd like to thank ALL the reviewers for their valuable feedbacks (I've lost count how many of you there were). It's great to see fungi highlighted in the plant journal where I published my first paper on legumes and rhizobia. https://nph.onlinelibrary.wiley.com/doi/abs/10.1111/nph.16709