I’ll be presenting some papers I find interesting here on the blog. This is mainly as a way for me to semi-formalize my thoughts about research and communicate these thoughts with you, but also to keep me on track with my reading. There is so much amazing science happening it’s almost too much effort to keep track of, but I am going to attempt to, at least in this public forum. These posts will be just as much for my benefit as they will be as ways for you, as the reader, to find out about what is new and interesting, at least what is new and interesting to me…
I’d like to first focus on a paper co-authored by some of my colleagues at Penn State. The Kao Lab has long studied self-incompatibility in plants, mainly using Petunia as a model species for this work. Petunia is a member of the Solanaceae and shares close common relatives with Tomatoes, Potatoes, and Eggplants. The Kao lab has co-authored numerous papers with the Takayama Lab at the Nara Institute of Science and Technology in Japan. This latest paper was published in the journal Science this month.
Plants, of course, can’t move from one place to another to look for a suitable mate with genes for advantageous traits. As the apple doesn’t fall far from the tree, many plants in a specific area will be defined by very similar sets of genes. Plants that breed with genetic relatives may face some of the same fates as those noted in the animal kingdom: predominance of genetic diseases, a decrease in fitness and overall health, and an inability to survive against stresses and pathogens. Therefore, plants have evolved specific mechanisms for reducing or preventing inbreeding depression.
Prior research from the Kao Lab had elucidated two gene types responsible for the prevention of inbreeding, in what has become known as self-incompatibility. One gene first identified in 1994, is an S-RNase, and is responsible for stopping gene expression in pollen grains similar to the flower it arrives at. Another set of genes identified in 2004, SLFs (S-Locus F-box proteins), are found expressed in pollen and regulate self-incompatibility by specifically “disengaging” the S-RNase found in the flower pistil. These two groups of genes work in collaboration to initiate self-incompatibility in the Petunia flower.
This new paper in the journal Science by Kubo et al. identifies a larger suite of SLF genes and adds more detail to the picture of self-incompatibility. In addition to the SLF protein described in 2004, an additional 5 types of SLF genes have been elucidated in this paper. The increased diversity of SLF proteins explains how elaborate this mechanism of self-incompatibility is. There is a commentary on this research here in the same journal.