Beechdrops

I was writing about hay-rattle Rhinanthus minor a peculiarly desirable meadow flower parasitic on grasses. Digging a bit revealed that it was part of  Family Orobanchaceae. Dang! that rings a bell I thought . . . but a distant one. The family name derives from the Greek ὄροβος (vetch, a legume) + ἄγχω (strangler). And that's the key to the family's success. Their roots invade the roots of grasses and legumes to dine off the products of their host's photosynthesis - collapse of grass, which allows other meadow species to thrive in the gaps. Orobanchs all engage in parasitism but some, like hay-rattle, do not inhale and retain the ability to photosynthesize. 

When we came back to Ireland in 1990, the TCD lab in which I started to work had just emptied of a clatter of exceptionally smart scientists who all, eventually, became Full Professors at UCD, the Other University.

One of them, Ken Wolfe, signed up as a PostDoc in Jeff Palmer's Bloomington Indiana lab; tasked to investigate what happens to the photosynthetic apparatus when a plant is no longer required to capture energy from the sun because it's gone full-metal parasite on its neighbours. This required Ken to learn which end of an eppendorf would open and how to extract and process DNA from a homogenate of tissue. He was notably more successful than me in his temporary sojourn as a real [white coat, safety glasses] scientist. In those couple of years, he mastered a whole new toolkit and sequenced the chloroplast genome of Epifagus virginiana [L in Arkansas pic by Eric Hunt] an Orobanch which is an obligate parasite on the roots of Fagus grandifolia the American beech: no other species will do.

If you are adept in the language of molecular biology you can read the whole PNAS paper. Function and evolution of a minimal plastid genome from a nonphotosynthetic parasitic plant.  tl;dr chloroplasts, originally free-living bacteria, have their own reduced genome consisting of a) a bunch of genes to make energy-capture proteins b) another bunch of genes to switch on the 'business' genes. Epifagus, no longer bothered about photosynthesis, has lost about 2/3s of the normal chloroplast genome. This suggests that chloroplasts do something else as well as energy capture. But the plant could also be still in the process of shedding baggage. That's a neat story about the pattern and process of evolution, all tied up from a standing start in two years.

Wolfe returned to our alma mater after his been-to years in the USA and played to his strengths as a computational evolutionary biologist, leaving the generation of primary data to others. Through the rest of the 90s he did World-class beautifully illustrated work on the yeast Saccharomyces cerevisiae genome. and also contributed to The Paper delivering the human genome.

At the turn of this century he became my direct boss which permitted me fly-on-the-wall status as another generation of brilliant people chipped away at the coal-face of science while I watched. I think I earned my salt; but not really in a tangible papers-and-grants way. None of my three good ideas in science happened during that gig. But I really learned a lot and continue to be grateful for being giving a seat at the table.