Development of novel robotic platforms for mechanical stress induction, and their effects on plant morphology, elements, and metabolism

Abstract

This research evaluates the effect on herbal crops of mechanical stress induced by two specially developed robotic platforms. The changes in plant morphology, metabolite profiles, and element content are evaluated in a series of three empirical experiments, conducted in greenhouse and CNC growing bed conditions, for the case of basil plant growth. Results show significant changes in morphological features, including shortening of overall stem length by up to 40% and inter-node distances by up to 80%, for plants treated with a robotic mechanical stress-induction protocol, compared to control groups. Treated plants showed a significant increase in element absorption, by 20–250% compared to controls, and changes in the metabolite profiles suggested an improvement in plants’ nutritional profiles. These results suggest that repetitive, robotic, mechanical stimuli could be potentially beneficial for plants’ nutritional and taste properties, and could be performed with no human intervention (and therefore labor cost). The changes in morphological aspects of the plant could potentially replace practices involving chemical treatment of the plants, leading to more sustainable crop production.

Improving Tomato Productivity for Changing Climatic and Environmental Stress Conditions

“…Several other production style methods have developed that include soft clothes [96], motion vibrators [97], roll-table system [98]. More recently, in a well-devised experimental design, the authors used two different robotic platforms for investigating the potential of automation in a MS study [99,100]. In the first case, a seven-DoF Franka Emika robotic arm, equipped with a stroking end-effector consisting of a row of plastic strings, was placed in a greenhouse setting.…”

“…Further, MS treatments resulted in increased DHA (Dehydroascorbic acid) and GABA levels. The authors concluded that increases in these metabolites is linked to build up of ROS and changes in nitrogen metabolism and aminoacid accumulation with mechanical induced abiotic stress [99,100]. In another interesting application, a model automated touch machine was designed for the purpose of studying the effect of touch response in Arabidopsis thaliana [101].…”

Biochemical and Physiological Responses of Arabidopsis thaliana Leaves to Moderate Mechanical Stimulation

“…Moreover, mechanically-induced stress can increase the content of specialized metabolites and antioxidant capacity of leafy vegetables [13]. It has also been reported [18] that mechanical stimulation can improve the nutritional properties of plants by increasing the absorption of elements and changes in metabolite profile. In addition, mechanical stimulation has been shown to lead to acclimation and tolerance to other stress conditions such as frost, cold, heat, salt, drought, and pathogen attack [19,20].…”

“…The studies conducted so far included different types of mechanical stimuli, however they were rarely quantified, making it difficult to compare data from different studies as pointed out by Coutand [65]. In most cases, mechanical stimuli have been quantified as the number of rubbing [22], touching [21], bending [66], and brushing treatments [15], and these studies have focused mainly on the effects on growth, morphological, and developmental changes [18,67]. Unlike these long-term effects, mechanical stimulation triggers numerous physiological and biochemical changes that can be detected in a much shorter time than phenotypic modifications.…”