Screening technique uncovers five new plant activator compounds

Sep 11, 2012
Figure 1 shows the molecular structure of imprimatins. Credit: RIKEN

A new high-throughput screening technique developed by researchers at the RIKEN Plant Science Center (PSC) has been used to uncover five novel immune-priming compounds in Arabidopsis plants. Discovery of the compounds, which enhance disease resistance without impacting plant growth or crop yield, establishes the new technique as a powerful asset in the battle to protect crops from damaging pathogens.

Plant activators, compounds that activate a plant's immune system in response to invasion by pathogens, play a crucial role in crop survival by triggering a range of immune responses. Unlike pesticides, plant activators are not pathogen specific and also not affected by , making them ideal for use in agriculture. Wet-rice farmers across East Asia use plant activators as a sustainable means to enhance crop durability without the of microbial pesticides.

One of the key problems of plant activators, however, is that the activation of plant responses they trigger is often associated with arrested growth and reductions in crop yield. Determining why this is so is difficult because despite their widespread use, the governing how plant activators work are largely unknown.

Figure 2 shows the original screening method for immune response modulators. Credit: RIKEN

The new developed by the PSC team overcomes this challenge by distinguishing between compounds that induce immune responses on their own from those that do so exclusively in the presence of a pathogen. The former class of compounds, which includes known plant activators, can be toxic to cells and was thus eliminated in the screening. The resulting five compounds, identified from a total of 10,000 compounds screened, enhance resistance against pathogenic Pseudomonas bacteria by priming without directly activating defense genes.

Figure 3 shows plant immunity signaling and the action point of Imprimatins. Credit: RIKEN

Further investigation revealed that the five compounds inhibit two enzymes that inactivate the defense hormone salicylic acid (SA glucosyltransferases or SAGTs), and gene knockout experiments confirmed that plants without these enzymes exhibit enhanced . Together, the results establish the effectiveness of the new technique for finding useful plant activators and the power of SA metabolism as a strategy for crop protection.

Explore further: Chickens to chili peppers: Scientists search for the first genetic engineers

More information: Yoshiteru Noutoshi, Masateru Okazaki, Tatsuya Kida, Yuta Nishina, Yoshihiko Morishita, Takumi Ogawa, Hideyuki Suzuki, Daisuke Shibata, Yusuke Jikumaru, Atsushi Hanada, Yuji Kamiya, and Ken Shirasu. Novel Plant Immune-Priming Compounds Identified via High-Throughput Chemical Screening Target Salicylic Acid Glucosyltransferases in Arabidopsis. The Plant Cell, 2012. DOI: doi/10.1105/tpc.112.098343

add to favorites email to friend print save as pdf

Related Stories

Tomato stands firm in face of fungus

May 09, 2008

Scientists at the University of Amsterdam have discovered how to keep one’s tomatoes from wilting – the answer lies at the molecular level. The story of how the plant beat the pathogen, and what it means for combating ...

How do plants fight disease?

Mar 28, 2011

How exactly bacterial pathogens cause diseases in plants remains a mystery and continues to frustrate scientists working to solve this problem. Now Wenbo Ma, a young plant pathologist at the University of ...

Recommended for you

Deadly human pathogen Cryptococcus fully sequenced

6 hours ago

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...

Building better soybeans for a hot, dry, hungry world

Apr 16, 2014

(Phys.org) —A new study shows that soybean plants can be redesigned to increase crop yields while requiring less water and helping to offset greenhouse gas warming. The study is the first to demonstrate ...

User comments : 0

More news stories

Deadly human pathogen Cryptococcus fully sequenced

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...