Search for: All records

Abstract Organ chirality in plants has been linked to cytoskeletal organization, as demonstrated in Arabidopsis twisted mutants, where left-skewed cortical microtubules are associated with right-handed twisting, and vice versa. While this phenotype seemingly mirrors vining habits, the hypothesis remains understudied within naturally twining plants. Qualitative observations have identified skewed microtubules in the twining stem of Ipomoea nil (L.) Roth vine, suggesting parallels with Arabidopsis studies. To further investigate organ chirality in twining plants, we used common bean vine (Phaseolus vulgaris L.) to examine the relationship between microtubule orientation, cell morphogenesis, and the right-handed twining phenotype via immunolabeling techniques. Here, we report a transition from mixed microtubule orientations in emergent and elongating internodes to a predominance of longitudinal microtubules in straight and twined stem segments post-elongation. Additionally, we report a distinction in epidermal cell shapes, where straight portions of the stem consist of lobes with rectangular cells and furrows with round cells, while twined portions comprise cells that are relatively more rectangular and stretched. We propose that these orientations reflect dynamic microtubule responses to external stimuli and growth cues, such as tensile stresses from climbing or tissue expansion. Taken together, these findings highlight dissimilarities between twisting Arabidopsis mutants and naturally twining plants. 

These are the data used to generate the figures associated with the paper: Helical Growth of Twining Common Bean is Associated with Longitudinal, Not Skewed, Microtubule Patterning.   All associated scripts can be found here: https://github.com/angelique-acevedo/Microtubule-Twining-Analysis 

Internode_lengths_AveragePerGroup_Stage5.csv = averaged internode lengths for each treatment groups at stage 5  (plastochron 9). Data represented in Appendix S2. Internode_lengths_Stage5.csv = data of all internodes lengths per individual plant at stage 5 (plastochron 9). Data represented in Appendix S2. InternodeLengths_allStages.csv = internode lengths through 5 stages (0-9 plastochon). Data represented in Appendix S1. Associated scripts: https://github.com/angelique-acevedo/Common-Bean-Analysis 

Abstract PremiseGelatinous (G)‐fibers are specialized fibers that generate tensile force to bend and straighten many plant organs; this phenomenon has been intensively studied in tension wood of trees. Previous work has shown that G‐fibers are common within the stems of twining vines, but we lack the spatiotemporal developmental data required to determine whether, or how, G‐fibers contribute to the movement and/or stabilization of twining tissues. MethodsWe employed multiple histochemical approaches to characterize the formation and cell wall architecture of G‐fibers in twining and shrub phenotypes of common bean across a developmental time series. ResultsWithin an internode, G‐fibers first formed asymmetrically via differentiation of pericyclic fibers on the concave side of an existing bend and later arose erratically from the vascular cambium. G‐fibers were absent in immature and/or actively circumnutating internodes, thus validating previous reports that G‐fibers are not involved in rapid dynamic movements. Instead, G‐fibers formed in stationary internodes, where they developed (1) in an alternating asymmetric pattern, likely to support the posture maintenance of erect internodes at the base of twiners and throughout the length of shrubs or (2) on the concave side of twined internodes to stabilize their helical conformation. ConclusionsOur spatiotemporal results indicate that common bean vines form G‐fibers after an internode has fully elongated and becomes stationary, thus functioning to stabilize the posture of subtle bends and coil internodes. These results contribute to understanding how twining vines establish and maintain a grip on their host or supporting structure.