Root Tropism

Miyazawa, Yutaka; Yamazaki, T.; Moriwaki, Teppei; Takahashi, Hideyuki

doi:10.1016/b978-0-12-387692-8.00010-2

Cited by 12 publications

(4 citation statements)

References 125 publications

(123 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…LRs display growth tropisms in response to gravity, light, touch and moisture gradients that contribute to enhancing plant growth by increasing nutrient capture from the soil [37]. Although LR distribution in Arabidopsis has been linked to the waving growth pattern of the PR through asymmetric auxin accumulation [38], the LRs in tomato did not show a preference to growing on the outside edge of the PR (Figure S3).…”

Section: Resultsmentioning

confidence: 99%

Morphological Characterization of Root System Architecture in Diverse Tomato Genotypes during Early Growth

Alaguero-Cordovilla

Gran-Gómez

Tormos-Moltó

et al. 2018

IJMS

View full text Add to dashboard Cite

Plant roots exploit morphological plasticity to adapt and respond to different soil environments. We characterized the root system architecture of nine wild tomato species and four cultivated tomato (Solanum lycopersicum L.) varieties during early growth in a controlled environment. Additionally, the root system architecture of six near-isogenic lines from the tomato ‘Micro-Tom’ mutant collection was also studied. These lines were affected in key genes of ethylene, abscisic acid, and anthocyanin pathways. We found extensive differences between the studied lines for a number of meaningful morphological traits, such as lateral root distribution, lateral root length or adventitious root development, which might represent adaptations to local soil conditions during speciation and subsequent domestication. Taken together, our results provide a general quantitative framework for comparing root system architecture in tomato seedlings and other related species.

show abstract

Section: Resultsmentioning

confidence: 99%

Morphological Characterization of Root System Architecture in Diverse Tomato Genotypes during Early Growth

Alaguero-Cordovilla

Gran-Gómez

Tormos-Moltó

et al. 2018

IJMS

View full text Add to dashboard Cite

show abstract

“…Such results support what observed by Newcombe and Rhodes at the beginning of the last century (Newcombe and Rhodes, 1904). From an ecological point of view, the search for anchoring and for water is a beneficial adaptive trait guiding the choices of radicle during seedling development (Bengough et al, 2011; Miyazawa et al, 2011). Although chemotropism of primary roots could be limited by the presence of endosperm in seeds that supports the demand for nutrients during germination, root development is influenced by nutrient supply and represents a useful adaptation in maximizing nutrient acquisition and tolerating unfavorable soils (Forde and Lorenzo, 2001; Ruiz Herrera et al, 2015).…”

Section: Discussionmentioning

confidence: 99%

Chemotropic vs Hydrotropic Stimuli for Root Growth Orientation in Microgravity

et al. 2019

View full text Add to dashboard Cite

Understanding how plants respond to spaceflight and extraterrestrial environments is crucial to develop life-support systems intended for long-term human explorations. Gravity is a main factor influencing root development and orientation, typically masking other tropisms. Considering that reduced levels of gravity affect many plant responses in space, the interaction of other tropic stimuli in microgravity represents the frontier to be investigated aiming at life-support systems optimization. In this paper we report on MULTITROP (Multiple-Tropism: interaction of gravity, nutrient and water stimuli for root orientation in microgravity), an experiment performed on the International Space Station during the Expedition 52/53. Scientific aim of the experiment was to disentangle hydrotropism from chemotropism for root orientation in absence of the gravity stimulus. Among several species relevant to space farming, Daucus carota was selected for the experiment because of its suitability with the experimental hardware and setup. At launch site, carrot seeds were placed between two disks of inert substrate (one imbibed with water and the other with a disodium phosphate solution) and integrated into a hardware developed, refurbished and flight-certificated by Kayser Italia. Post-flight, a Ground Reference Experiment was performed. Root development and orientation of seedlings grown in microgravity and at 1g condition were measured through 3D-image analysis procedures after imaging with X-ray microtomography. Radicle protruded preferentially from the ventral side of the seed due to the asymmetric position of the embryo. Such a phenomenon did not prevent the achievement of MULTITROP scientific goal but should be considered for further experiments on radicle growth orientation in microgravity. The experiment conducted in space verified that the primary root of carrot shows a positive chemotropism towards disodium phosphate solution in the absence of the gravity stimulus. On Earth, the positive chemotropism was masked by the dominant effect of gravity and roots developed downward regardless of the presence/absence of nutrients in the substrate. Taking advantage of altered gravity conditions and using other chemical compounds, further studies should be performed to deepen our understanding of root chemotropic response and its interaction with other tropisms.

show abstract

“…Water acquisition is an important function of plant roots (Miyazawa et al, 2011). Because water availability in the soil is often spatially and temporally patchy, roots of many species can exert directional root growth toward water; i.e., hydrotropism.…”

Section: Hydrotropismmentioning

confidence: 99%

Root Tropisms: Investigations on Earth and in Space to Unravel Plant Growth Direction

et al. 2020

View full text Add to dashboard Cite

Root tropisms are important responses of plants, allowing them to adapt their growth direction. Research on plant tropisms is indispensable for future space programs that envisage plant-based life support systems for long-term missions and planet colonization. Root tropisms encompass responses toward or away from different environmental stimuli, with an underexplored level of mechanistic divergence. Research into signaling events that coordinate tropistic responses is complicated by the consistent coincidence of various environmental stimuli, often interacting via shared signaling mechanisms. On Earth the major determinant of root growth direction is the gravitational vector, acting through gravitropism and overruling most other tropistic responses to environmental stimuli. Critical advancements in the understanding of root tropisms have been achieved nullifying the gravitropic dominance with experiments performed in the microgravity environment. In this review, we summarize current knowledge on root tropisms to different environmental stimuli. We highlight that the term tropism must be used with care, because it can be easily confused with a change in root growth direction due to asymmetrical damage to the root, as can occur in apparent chemotropism, electrotropism, and magnetotropism. Clearly, the use of Arabidopsis thaliana as a model for tropism research contributed much to our understanding of the underlying regulatory processes and signaling events. However, pronounced differences in tropisms exist among species, and we argue that these should be further investigated to get a more comprehensive view of the signaling pathways and sensors. Finally, we point out that the Cholodny-Went theory of asymmetric auxin distribution remains to be the central and unifying tropistic mechanism after 100 years. Nevertheless, it becomes increasingly clear that the theory is not applicable to all root tropistic responses, and we propose further research to unravel commonalities and differences in the molecular and physiological processes orchestrating root tropisms.

show abstract

Root Tropism

Cited by 12 publications

References 125 publications

Morphological Characterization of Root System Architecture in Diverse Tomato Genotypes during Early Growth

Morphological Characterization of Root System Architecture in Diverse Tomato Genotypes during Early Growth

Chemotropic vs Hydrotropic Stimuli for Root Growth Orientation in Microgravity

Root Tropisms: Investigations on Earth and in Space to Unravel Plant Growth Direction

Contact Info

Product

Resources

About