A retrospective of an unconventionally trained plant pathologist: plant diseases to molecular plant pathology.

Plant pathology evolved from its mycology-oriented origins into a science dealing with biochemical mechanisms of diseases, along with enhanced crop production through disease control. This retrospective describes first my personal experience from my introduction to plant pathology, to the establishment of the concept of accessibility as a model pertaining to genetically defined basic compatibility induced by pathogens. I then refer to the development of molecular plant pathology from physiological and biochemical plant pathology fostered by the growth in recombinant technology in the second half of the past century. This progress was best reflected by the U.S.-Japan Seminar Series held at 4-5-year intervals from 1966 to 2003 and documented by publications in major journals of our discipline. These seminars emphasized that progress in science has always been supported by the invention of novel techniques and that knowledge integrated from modern genomics and subsequent proteomics should contribute to the progress of basic life sciences and, more importantly, to the elaboration of rational measures for disease control.

Molecular analysis and characterization of the Cochliobolus heterostrophus beta-tubulin gene and its possible role in conferring resistance to benomyl.

Cochliobolus heterostrophus Tub1 described here is the first beta-tubulin gene characterized from a naturally occurring benomyl-resistant ascomycete plant pathogen. The gene encodes a protein of 447 amino acids. The coding region of Tub1 is interrupted by three introns, of 116, 55, and 56 nt, situated after codons 4, 12, and 53, respectively. As a result of the preference for pyrimidines in the third position of the codons when a choice exists between purines and pyrimidines, codon usage in the Tub1 gene is biased. Tub1 shows high homology with beta-tubulin genes of other ascomycete species. However, Tub1 is exceptional in having Tyr(167), compared with Phe(167), possessed by beta-tubulin genes of other ascomycetes sequenced thus far. The Tyr(167) residue has been associated with benomyl resistance in other organisms. In contrast, all other benomyl-implicated residues of Tub1 correspond to sensitivity. Based on these results, we suggest that benomyl resistance in the fungus probably is attributed to Tyr(167).