Periodic Reporting for period 4 - GAtransport (A direct, multi-faceted approach to investigate plant hormones spatial regulation: the case of gibberellins)
Periodo di rendicontazione: 2020-08-01 al 2022-01-31
Plant hormones are small signaling molecules that direct key processes in plants’ development and adaptive growth, including in crop species. For example, during the so-called 'green revolution', high-yielding cultivars of maize, wheat, and rice, which revolutionized these grains world productivity, were identified as mutants in biosynthesis or signaling of the plant hormone gibberellin. Thus, understanding the details of gibberellins dynamics in plants has significant research importance with potential practical implications on agriculture, food security and human health. To date, very little information exists on how plants regulate the movement of gibberellins to insure their arrival in the right place, time and concentration so that proper growth and development can be achieved.
The overall goal of the proposed research was to elucidate and characterize GA flow in plants and identify the mechanisms controlling it.
Towards this goal, we developed several tools that facilitate imaging and manipulation of gibberellins in live, whole plants, Using these tools, we and others were able to map accumulation sites of gibberellins in different plant species and identify several gibberellins transporters, including the first one to be validated in planta.
The main conclusion from the project is that gibberellins are indeed actively transported in plants and that an elaborate transport mechsnim to control their flow exists. This discoery not only has fundamental implications for basic research of gibberellins, but also has potential practical applications. Gibberellins regulate many important traits in crops and the abiliy to influence on their function via intervention in transport opens the door for development of novel agrochemicals for agricultural use.
The overall goal of the proposed research was to elucidate and characterize GA flow in plants and identify the mechanisms controlling it.
Towards this goal, we developed several tools that facilitate imaging and manipulation of gibberellins in live, whole plants, Using these tools, we and others were able to map accumulation sites of gibberellins in different plant species and identify several gibberellins transporters, including the first one to be validated in planta.
The main conclusion from the project is that gibberellins are indeed actively transported in plants and that an elaborate transport mechsnim to control their flow exists. This discoery not only has fundamental implications for basic research of gibberellins, but also has potential practical applications. Gibberellins regulate many important traits in crops and the abiliy to influence on their function via intervention in transport opens the door for development of novel agrochemicals for agricultural use.
To address the first objective, we developed gibberellins tagged with a fluorescent marker that enable their visualization in plants via microscopy. We and others applied these tagged derivatives to different plant species to uncover the distribution patterns and accumulation sites of gibberellins in each plant, focusing mainly on Arabidopsis thaliana but also, for example, on potatoes. To address the second objective, we developed two platforms that enable to generate gibberellins at known locations in the plant and in defined time so that their movement thereof could be studied and quantified. The first platform, which utilize light to generate gibberellins, is now established in its first version. This platform was used to generate gibberellins in different locations in plant roots (Arabidopsis thaliana) and quantify parameters of their movement. We are still working on developing a second generation of the platform as well as utilizing the existing one to extract more information on gibberellins flow. To address the third objective, we applied two approaches to screen for proteins that regulate gibberellins flow. In the first, we used the fluorescently tagged gibberellins to identify one protein transporter of gibberellins in plants. The identified transporter was studied and a report on its discovery and characterization is published. This platform did not reveal additional transportes yet it served to verify transporters that were identified by other means. In the second platfrom, using chemical techniques to identify transporters, the required molecules and assays to implement this approach are now established and ready for use.
At the beginning of the project, very little was known on the biodistribution of giberellins in plants and their active transport was only suspected.
This project expected outcomes were: 1) map the accumulation sites of bioactive gibberellins and their immediate precursors in Arabidopsis thaliana and identify sites where they play a functional role. 2) Define and quantitate gibberellins flow pathways in Arabidopsis thaliana roots. 3) Identify novel gibberellin transporters and novel gibberellin-binding proteins. 4) Establish innovative techniques to explore gibberellins mobility in Arabidopsis and in additional plant species.
We have made progress on all aspects. We first generated tools that enable to monitor
The outcomes of this project can be described on several levels: first, the tools we developed throughout this project enable us and others to study gibberellins at a much depper level than previously possible. One of their main advantage is their transferability acroos plant species, which opens the door to studying this plant hormone in crops. Second, we provided new insights and gibberellins flow and accumulation sited, and identified some of the proteins that govern these distibution patterns. Finally, our work further established the transport of gibberellins as an integral regulation layer that plants exert over the function of this important hormone. I expect that these contributions will have a long-lasting impact on the field and open further opportunities in research and practival applications.
This project expected outcomes were: 1) map the accumulation sites of bioactive gibberellins and their immediate precursors in Arabidopsis thaliana and identify sites where they play a functional role. 2) Define and quantitate gibberellins flow pathways in Arabidopsis thaliana roots. 3) Identify novel gibberellin transporters and novel gibberellin-binding proteins. 4) Establish innovative techniques to explore gibberellins mobility in Arabidopsis and in additional plant species.
We have made progress on all aspects. We first generated tools that enable to monitor
The outcomes of this project can be described on several levels: first, the tools we developed throughout this project enable us and others to study gibberellins at a much depper level than previously possible. One of their main advantage is their transferability acroos plant species, which opens the door to studying this plant hormone in crops. Second, we provided new insights and gibberellins flow and accumulation sited, and identified some of the proteins that govern these distibution patterns. Finally, our work further established the transport of gibberellins as an integral regulation layer that plants exert over the function of this important hormone. I expect that these contributions will have a long-lasting impact on the field and open further opportunities in research and practival applications.