Drought is one of the major environment factors that threatens future food security. In plants, stomatal pores expel 200 molecules of water for every carbon-dioxide molecule that is fixed during photosynthesis. Under drought conditions, plant hormone abscisic acid (ABA) activates its receptors, eventually leading to stomata closure and reduced water loss. Therefore, it is critical to understand the molecular process behind perceptions of plant hormones that regulate opening and closing of guard cells. In a recent study from our group published in Structure, we describe the mechanism of plant hormone perception that leads to initiation of drought resistance signaling.

Since 2009, several ABA-mimicking agrochemicals such as pyrabactin and quinabactin were discovered which can target ABA receptors. Chemical control of ABA receptors is thereby a promising strategy to modulate plant drought tolerance.

Despite progresses in understanding ABA signaling, a complete molecular picture of ABA recognition by the receptors is still lacking. Our study uses atomistic simulations to investigate ABA-mediated activation of two subtype ABA receptors from Arabidopsis thaliana. We have identified the pathways and the energetic landscapes of ABA binding and receptor activations, leading to unique insights into hormone perception.

The video depicts the process of plant hormone (ABA) binding to its receptor. The plot on the left shows the free energy landscapes associated with the process. Free energy indicates the probability of observing a particular conformation of the ligand and protein.

Interestingly, we have found that ABA binding is a necessary but insufficient condition for full receptor activation. A large energy barrier for ABA binding is observed, which is associated with the exclusion of water molecules from the receptor binding pocket.

Our results also show that post-translational modification of ABA receptor prevents ABA binding and renders current agrochemicals ineffective on ABA receptor activation.

Our findings open up new possibility for selective modulation of ABA receptors and design of new agrochemicals for effective control of drought resistance in plants.  

The paper is available online on the cell press website.

  Category: Research

19 posts
January 24th, 2019

How do plants perceive hormones to activate drought resistance ?

Drought is one of the major environment factors that threatens future food security. In plants, stomatal pores expel 200 molecules […]

December 27th, 2017

Meet Jiangyan Feng, ChBE Graduate student, Fall 2016.

July 20th, 2017

2017 Summer Undergraduate Research Experiences in Shukla Group.

July 13th, 2017

Meet our group members: Moeen Meigooni, ChBE ’17

July 12th, 2017

Visiting student: Jiming Chen, BS, ChBE, Rice University, 2017

July 12th, 2017

Meet our group members: Faisal Aldukhi, ChBE ’19

July 12th, 2017

Meet our group members: Qihua Chen, MatSE’18, Blue Waters Intern 2017-18

June 28th, 2017

Shriyaa Mittal’s 2017 CSE Fellow.

June 28th, 2017

Balaji Selvam’s talk at the 2017 Blue Waters Symposium.

September 25th, 2016

Summer Intern Nikhil Sethia’s (IIT Delhi) Post on his experiences in Shukla Group.

September 25th, 2016

Prof. Shukla’s talk on “Molecular Models of Nitrate Transport in Plants” at Plants in silico Symposium, 2016.

September 25th, 2016

Talk by Graduate Student Alex Moffett at 2016 Blue Waters Symposium at Sunriver Resort, Oregon.

December 21st, 2015

Research Talk by Prof. Shukla (CSE Seminar Series, Fall 2015)

July 20th, 2015

Research talk by Diwakar (Blue Waters Symposium, Jun 2015)

July 17th, 2015

Plants in silico: a multi-scale modeling platform

May 30th, 2014

Central themes of our research group

March 11th, 2014

Recent paper on the key cellular signaling proteins in Cancer highlighted in several news articles

February 1st, 2014

GPCR activation work highlighted in Nature Methods and Nature Reviews Drug Discovery journals.

January 1st, 2014

Nature Chemistry article highlighted across scientific news blogs.