Poster: Cytoskeleton: Structure & Function

Abs # 1109: A putative kinesin light chain alters plant growth and chloroplast morphology in Arabidopsis thaliana

Presenter:	Gruver, Amanda L, alg220@psu.edu
Authors	Gruver, Amanda L (A)   Hillwig, Matthew L (A)   Campbell, Michael A (A)
Affiliations:	(A): Penn State Erie

A random clone (NDP1) 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. Microarray analysis revealed that NDP1 transcript levels were similar in dormant and actively growing potato meristems. 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 kinesin light chain proteins in Nostoc sp. Examination of an A. thaliana T-DNA knockout mutant of the NDP1 locus reveals that the loss of NDP1 resulted in growth rate reduction of 93% in comparison to controls. Additionally, loss of NDP1 results in an increased sensitivity to salt. The ndp1 and control plants exhibited a similar level of pigmentation when grown at light intensities of 20 mmol m^-2 s^-1 but NDP1 plants grown at a light intensity of 100 mmol m^-2 s^-1 exhibited a darker pigmentation in comparison to the wild type. Microscopic examination of NDP1 revealed that mesophyll cells contain a similar number of chloroplasts per cell but the morphology of the chloroplasts is altered. We hypothesize that NDP1 encodes for a putative kinesin light chain that may interact with the photosynthetic apparatus.