An Arabidopsis thaliana tubulin mutant with conditional root-skewing phenotype
Low doses of microtubule-interacting drugs cause wild-type Arabidopsis thaliana seedling roots to twist in a left-handed helical direction. We here report molecular characterization of an A. thaliana tubulin mutant whose roots twist in a right-handed direction and have shallow left-handed cortical microtubule arrays when challenged with low doses of microtubule drugs. In the absence of the drug, growth and development of the mutant was apparently normal. In this conditional twisting mutant, Cys213 of α-tubulin6 was exchanged with Tyr. The mutant tubulin was incorporated into the microtubule polymer with wild-type tubulins, and thus acted as a dominant-negative mutation. These results suggest that compromised microtubules in wild-type and mutant roots are qualitatively distinct and affect skewing direction differently.
KeywordsArabidopsis thaliana Propyzamide Tubulin Twist
We thank T. Nakagawa (Shimane University) for pGWB2. This work was partly supported by grants from the Ministry of Education, Culture, Sports, Science and Technology of Japan (1702718 and 18370020), and by a grant for Ground-based Research for Space Utilization from Japan Space Forum.