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ARS Home » Northeast Area » Kearneysville, West Virginia » Appalachian Fruit Research Laboratory » Innovative Fruit Production, Improvement, and Protection » Research » Publications at this Location » Publication #330430
Title: DRO1 influences root system architecture in Arabidopsis and Prunus species

Author
item Waite, Jessica
item Webb, Kevin
item Srinivasan, Chinnathambi
item Dardick, Christopher - Chris

Submitted to: Plant Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/16/2016
Publication Date: 3/4/2017
Citation: Guseman, J.M., Webb, K.K., Srinivasan, C., Dardick, C.D. 2017. DRO1 influences root system architecture in Arabidopsis and Prunus species. Plant Journal. 89:1093-1105.

Interpretive Summary: Roots are essential for a plant to uptake water and nutrients, as well as provide anchoring within the soil. Deeper roots can allow the plant to reach more water and nitrogen, as these resources are more abundant in deeper soil layers; however, few genes have been identified that control the angle and depth of roots. We show that the gene, DEEPER ROOTING 1 (DRO1), is important for setting the angle and depth of roots in Arabidopsis and plum trees, and that it belongs to a family of genes that also control angles of shoot branches. DRO1 may be an important tool to generate trees with deeper roots to reach water and nitrogen, especially during dry seasons.

Technical Abstract: Roots provide essential uptake of water and nutrients from the soil, as well as anchorage and stability for the whole plant. Root orientation or angle is an important component of the overall architecture and depth of the root system; however, little is known about the genetic control of this trait. Recent reports in rice identified a role for DEEPER ROOTING 1(DRO1) in controlling the orientation of the root system, leading to positive changes in grain yields under drought conditions. Here, we found that DRO1 and DRO1-related genes are present across diverse plant phyla and fall within the IGT gene family. The IGT family also includes TAC1 and LAZY1, which are known to control the orientation of lateral shoots. Consistent with a potential role in root development, DRO1 homologues in Arabidopsis and peach showed root-specific expression. Promoter-reporter constructs revealed that AtDRO1 is predominantly expressed in both the root vasculature and root tips in a distinct developmental pattern. Mutation of AtDRO1 led to more horizontal lateral root angles. Over-expression of AtDRO1 under a constitutive promoter reduced lateral root angles and resulted in shoot phenotypes including upward leaf curling, shortened siliques, and narrow lateral branch angles. A conserved C-terminal EAR-like motif found in IGT genes was required for these ectopic phenotypes. Over-expression of PpeDRO1 in plum (Prunus domestica) led to deeper rooting phenotypes. Collectively, these data indicate a potential application for DRO1 related genes to alter root architecture for drought avoidance and improved resource utilization.