Genotypic recognition and spatial responses by rice roots Journal Article

Author(s): Fang, Suqin; Clark, Randy T; Zheng, Ying; Iyer-Pascuzzi, Anjali S; Weitz, Joshua S; Kochian, Leon V; Edelsbrunner, Herbert; Liao, Hong; Benfey, Philip N
Article Title: Genotypic recognition and spatial responses by rice roots
Affiliation IST Austria
Abstract: Root system growth and development is highly plastic and is influenced by the surrounding environment. Roots frequently grow in heterogeneous environments that include interactions from neighboring plants and physical impediments in the rhizosphere. To investigate how planting density and physical objects affect root system growth, we grew rice in a transparent gel system in close proximity with another plant or a physical object. Root systems were imaged and reconstructed in three dimensions. Root-root interaction strength was calculated using quantitative metrics that characterize the extent towhich the reconstructed root systems overlap each other. Surprisingly, we found the overlap of root systems of the same genotype was significantly higher than that of root systems of different genotypes. Root systems of the same genotype tended to grow toward each other but those of different genotypes appeared to avoid each other. Shoot separation experiments excluded the possibility of aerial interactions, suggesting root communication. Staggered plantings indicated that interactions likely occur at root tips in close proximity. Recognition of obstacles also occurred through root tips, but through physical contact in a size-dependent manner. These results indicate that root systems use two different forms of communication to recognize objects and alter root architecture: root-root recognition, possibly mediated through root exudates, and root-object recognition mediated by physical contact at the root tips. This finding suggests that root tips act as local sensors that integrate rhizosphere information into global root architectural changes.
Keywords: Imaging; 3D reconstruction; Kin recognition
Journal Title: PNAS
Volume: 110
Issue 7
ISSN: 1091-6490
Publisher: National Academy of Sciences  
Date Published: 2013-02-12
Start Page: 2670
End Page: 2675
DOI: 10.1073/pnas.1222821110
Notes: This work was supported by National Science Foundation Grant (Genome-Wide Analysis of Root Traits) DBI-0820624 (to P.N.B. and J.S.W.) and National Natural Science Foundation of China Grant 31025022 (to H.L.).J.S.W. holds a Career Award at the Scientific Interface from the Burroughs Wellcome Fund.
Open access: yes (repository)