Poster: Cytoskeleton structure & dynamics
Abs #
680: A putative kinesin light chain alters plant growth and chloroplast movement in Arabidopsis thaliana
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Presenter: |
Neuner, Russell D, rdn109@psu.edu |
Authors | Neuner, Russell D (A) Gruver, Amanda L (A) Johannes, Eva (B) Allen, Nina S (B) Campbell, Michael A (A) | | Affiliations: |
(A): Penn State Erie, The Behrend College, School of Science
(B): North Carolina State University, Department of Botany
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The clone (NDP1), which has sequence similarity to kinesin light chain (KLC), was isolated from a cDNA library produced from dormant potato meristems. The full-length cDNA was 1463 base pairs in length and encoded for a putative polypeptide composed of 421 amino acids. Further analysis on NDP1 was conducted in Arabidopsis thaliana because a single copy homologue exists at At5g02130. The A. thaliana and potato NDP1 homologues are highly similar and share greater than 50% identical and 73% conserved amino acids. BLAST analysis of both the A. thaliana and potato NDP1 genes demonstrated sequence similarities to KLC proteins in Nostoc sp., and the conserved KLC domain KOG1840. NDP1 expression, relative to ACT2 and GAPDH, was measured in A. thaliana using RT-PCR. Tissue specific expression demonstrated that NDP1 levels did not vary greater than 5-fold between roots, leaves, stalks, flowers, and siliques. NDP1 transcript levels were also measured in dark, 100 μmol/m2s and 200 μmol/m2s grown plants. Dark entrained plants exhibited a 50-fold decrease in NDP1 levels in comparison to ACT2, while light grown plants showed almost a 1:1 transcript ratio. This suggests that the expression of the NDP1 transcript is light regulated. Examination of an A. thaliana T-DNA knockout mutant of the At5g02130 locus revealed that the loss of NDP1 resulted in growth rate reduction of 93% in comparison to controls. Mutant ndp1 plants exposed to 200 μmol/m2s of light produced over seven times the anthocyanin seen in wild type plants and the rate of chloroplast movement was 93% reduced in ndp1 plants exposed to changes in light intensity. We hypothesize that NDP1 encodes for a putative kinesin light chain associated with chloroplast movement via the microtubule cytoskeletal components.
