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Root angle is controlled by EGT1in cereal crops employing anantigravitropic mechanism

Fusi, Riccardo; Rosignoli, Serena; Lou, Haoyu; Sangiorgi, Giuseppe; Bovina, Riccardo; Pattem, Jacob K.; Borkar, Aditi N.; Lombardi, Marco; Forestan, Cristian; Milner, Sara G.; Davis, Jayne L.; Lale, Aneesh; Kirschner, Gwendolyn K.; Swarup, Ranjan; Tassinari, Alberto; Pandey, Bipin K.; York, Larry M.; Atkinson, Brian S.; Sturrock, Craig J.; Mooney, Sacha J.; Hochholdinger, Frank; Tucker, Matthew R.; Himmelbach, Axel; Stein, Nils; Mascher, Martin; Nagel, Kerstin A.; De Gara, Laura; Simmonds, James; Uauy, Cristobal; Tuberosa, Roberto; Lynch, Jonathan P.; Yakubov, Gleb E.; Bennett, Malcolm J.; Bhosale, Rahul; Salvi, Silvio

Root angle is controlled by EGT1in cereal crops employing anantigravitropic mechanism Thumbnail


Serena Rosignoli

Haoyu Lou

Giuseppe Sangiorgi

Riccardo Bovina

Assistant Professor in Molecularbiochemistry & Biophysics

Marco Lombardi

Cristian Forestan

Sara G. Milner

Aneesh Lale

Gwendolyn K. Kirschner

Alberto Tassinari

Research Fellow

Brian S. Atkinson

Professor of Soil Physics

Frank Hochholdinger

Matthew R. Tucker

Axel Himmelbach

Nils Stein

Martin Mascher

Kerstin A. Nagel

Laura De Gara

James Simmonds

Cristobal Uauy

Roberto Tuberosa

Jonathan P. Lynch

Silvio Salvi


Root angle in crops represents a key trait for efficient capture of soil resources. Root angle is determined by competing gravitropic versus anti-gravitropic offset (AGO) mechanisms. Here we report a new root angle regulatory gene termed ENHANCED GRAVITROPISM1 (EGT1) that encodes a putative AGO component, whose loss of function enhances root gravitropism. Mutations in barley and wheat EGT1 genes confer a striking root phenotype, where every root class adopts a steeper growth angle. EGT1 encodes a F-box and Tubby domain containing protein which is highly conserved across plant species. Haplotype analysis found that natural allelic variation at the barley EGT1 locus impacts root angle. Gravitropic assays indicated that Hvegt1 roots bend more rapidly than wildtype. Transcript profiling revealed Hvegt1 roots deregulate ROS homeostasis and cell wall-loosening enzymes and cofactors. ROS imaging shown that Hvegt1 root basal meristem and elongation zone tissues have reduced levels. Atomic Force Microscopy measurements detected elongating Hvegt1 root cortical cell walls are significantly less stiff than wildtype. In situ analysis identified HvEGT1 is expressed in elongating cortical and stele tissues, which are distinct from known root gravitropic perception and response tissues in the columella and epidermis, respectively. We propose that EGT1 controls root angle by regulating cell wall stiffness in elongating root cortical tissue, counteracting the gravitropic machinery’s known ability to bend the root via its outermost tissues. We conclude that root angle is controlled by EGT1 in cereal crops employing a novel anti-gravitropic mechanism.


Fusi, R., Rosignoli, S., Lou, H., Sangiorgi, G., Bovina, R., Pattem, J. K., …Salvi, S. (2022). Root angle is controlled by EGT1in cereal crops employing anantigravitropic mechanism. Proceedings of the National Academy of Sciences,

Journal Article Type Article
Acceptance Date Jun 7, 2022
Online Publication Date Jul 26, 2022
Publication Date Jul 26, 2022
Deposit Date Jul 1, 2022
Publicly Available Date Jan 27, 2023
Journal Proceedings of the National Academy of Sciences
Print ISSN 0027-8424
Electronic ISSN 1091-6490
Publisher National Academy of Sciences
Peer Reviewed Peer Reviewed
Public URL
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