Publications by authors named "E M Spalding"

Rapid cell expansion pushes the Arabidopsis hypocotyl (juvenile stem) through the soil until blue light, acting first through phototropin 1 (phot1) and then through cryptochrome 1 (cry1), suppresses elongation to produce a length characteristic of established, photosynthetically capable seedlings. To determine where these two different blue-light receptors act to suppress hypocotyl elongation, we measured relative elemental growth rate, specifically along the hypocotyl midline at 5-min intervals before and during blue light, using a machine-learning-based image analysis pipeline designed specifically for this kinematic analysis of growth. In darkness, hypocotyl material expanded most rapidly (approximately 4% h) in a broad zone approximately 1 mm below the apical terminus of the hypocotyl (cotyledonary node).

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Cell expansion in a discrete region called the elongation zone drives root elongation. Analyzing time lapse images can quantify the expansion in kinematic terms as if it were fluid flow. We used horizontal microscopes to collect images from which custom software extracted the length of the elongation zone, the peak relative elemental growth rate (REGR) within it, the axial position of the REGR peak, and the root elongation rate.

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Plant roots elongate when cells produced in the apical meristem enter a transient period of rapid expansion. To measure the dynamic process of root cell expansion in the elongation zone, we captured digital images of growing Arabidopsis roots with horizontal microscopes and analyzed them with a custom image analysis program (PatchTrack) designed to track the growth-driven displacement of many closely spaced image patches. Fitting a flexible logistics equation to patch velocities plotted versus position along the root axis produced the length of the elongation zone (mm), peak relative elemental growth rate (% h), the axial position of the peak (mm from the tip), and average root elongation rate (mm h).

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Introduction: Quinoa is a high-value, nutritious crop that performs well in variable environments, marginal soils, and in diverse crop rotations. Quinoa's many attributes make it an ideal crop for supporting human health in global communities and economies. To date, quinoa research has largely focused on traits in adult plants important for enhancing plant phenotypic plasticity, abiotic stress, disease resistance, and yield.

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Quinoa ( Willd.), a pseudocereal with high protein quality originating from the Andean region of South America, has broad genetic variation and adaptability to diverse agroecological conditions, contributing to the potential to serve as a global keystone protein crop in a changing climate. However, the germplasm resources currently available to facilitate quinoa expansion worldwide are restricted to a small portion of quinoa's total genetic diversity, in part because of day-length sensitivity and issues related to seed sovereignty.

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