ISSN:
1432-2048
Keywords:
Cell wall expansion
;
Light, phototropism
;
Mutant (Phycomyces)
;
Phototropism, negative
;
Phycomyces
;
Sporangiophore
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The sporangiophore (spph) of a piloboloid mutant, genotype pil, of Phycomyces ceases elongation and expands radially in the growth zone shortly after reaching the developmental stage IV b. The pil spph is always negatively phototropic to unilateral visible light when its diameter exceeds 210 μm. Photoinduction of spph initiation, light-growth response, threshold of light energy fluence rate for the negative phototropism, avoidance and gravitropism in the pil mutant are all normal. In liquid paraffin, the pil spph shows negative phototropism as does the wild-type spph. Genetic analyses indicate that the negative phototropism of the pil mutant is governed by the phenotypic characteristics of pil but not by specific gene(s) responsible for negative phototropism. These facts imply that the reverse phototropism of the pil mutant results from a loss of the convergent lens effect of the cell because of the increase in cell diameter.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00410204
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