The Identification of Five Seedlings Hyper-responsive to Light (SHL), and Characterization of SHL7
Abstract
Light is one of the major environmental factors that controls plant development, through
a process known as photomorphogenesis. Plants perceive light via photoreceptors, and
the information used to direct a myriad of developmental responses. Analysis of mutants
defective in photomorphogenic responses elucidates the complex interactions between
light and plants. Previous genetic screens have yielded a class of mutants which exhibit
exaggerated responses to ambient light, designated shl (seedling hyper-responsive to
light). The following work encompasses the identification of five new shl mutants, a
detailed examination of one of these mutants (shl7), and of the SHL7 gene. The mutants
were isolated in a low-white light screen of seedlings derived from T-DNA mutagenesis.
Each of the mutants exhibits a heritable hyper-responsive phenotype in low-white light,
but displays minimal effects in darkness. For each, a putative site of T-DNA insertion has
been located. In addition to a low-white light phenotype, the shl7 mutant exhibits a mild
hyper-responsive phenotype to 670 nm red and 735 nm far-red light, but significant
hyper-responses to 420 nm blue light. SHL7 encodes a small, unique, and previously
undescribed protein annotated as At4g04925. GFP protein fusion analysis indicates that
the protein is localized to mitochondria.
Subject
photomorphogenesis cryptochromeCitation
Grum, Daniel S. (2008). The Identification of Five Seedlings Hyper-responsive to Light (SHL), and Characterization of SHL7. Doctoral dissertation, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2008 -08 -66.