CHARLOTTE GIBSON

The ‘hypersensitive response (HR)’ is a fundamental mechanism by which plants defend themselves against rust fungi and many other important pathogens. As soon as the plant cell recognises the potential danger it rapidly undergoes a series of chemical reactions that result in its own death but which present the pathogen with a chemically hostile environment.

In the last paper of his life (1905) Harry Marshall Ward described ongoing investigations which employed wheat varieties of different susceptibilities to rust and which were supplied by ‘Mr Biffen, working at our experimental farm…’. Marshall Ward’s conclusion was that [genes for] the hypersensitive response conferred immunity, although he warned against false immune responses (failed infections) that arose when the internal temperature of the leaf reached levels that directly inhibited fungal development (p38). 

On the centenary of the recognition of HR, Mur et. al. (2008) wrote that foremost among the ‘pioneering plant pathologists’ whose work led to such recognition was H Marshall Ward (see Ward 1902a). [He] ‘saw variable responses by wheat cultivars to leaf rust…while EC Gibson noted that varieties of Chrysanthemum which were resistant to [rust] hyphae exhibited localised plant cell death. Similar observations were made by Dorothea Marryat in the wheat-[yellow rust] pathosystem (Gibson 1904; Marryat 1907).’ 

What the quotation fails to explain is that, as Charlotte M Gibson (not EC Gibson) acknowledged, the infection studies forming the first part of her paper ‘originated in a suggestion made by Professor Marshall Ward’, under whose supervision the work was conducted. Dorothea Marryat’s paper  concludes, ‘…it was at the late Professor Marshall Ward’s suggestion that this investigation was undertaken, and owing to his kindness that I had the privilege of working in his laboratory’. Their studies built upon his observations; most critically, in his 1902a study of brown rust on Bromus spp., he had noted (p.298) that in incompatible combinations, ‘the cells first attacked die…the mycelium [of the rust fungus] cannot advance through the ruined tissues its ill-time ravages have brought about.’

There is little record of Charlotte Gibson. She does not appear to have been a ‘graduate’ of either Newnham or Girton Colleges. Since, in some of her papers, her name is followed by ‘B.Sc.’ she must have graduated from another university, possibly London. How she came to study with Harry Marshall Ward remains a mystery.  A later address for Charlotte is Bedford College, London (during which time she worked at the British Museum for Natural History, thanks to Mr and Mrs Anthony Gepp), while her last known address (1932) is Portsmouth Municipal College, the fore-runner of Portsmouth University, where she was employed as a lecturer. Charlotte did not continue with plant pathology. 

Next read Dorothea Marryat, where references may be found, or return to Women Inspired by Marshall Ward