Grassroots Vol 21 No 1 | Page 33

NEWS

Researchers reveal switch used in plant defense against animal attack

Decades of pursuit uncovers receptor , the product of an evolutionary arms race for survival , used by plants to sense herbivores

ScienceDaily

Current Address : University of California – San Diego Reprinted From : http :// bit . ly / 38dpuUu

For decades , scientists have known that plants protect themselves from the devastation of hungry caterpillars and other plant-munching animals through sophisticated response systems , the product of millions of years of evolution .

The biological mechanisms underlying this attack-counter defense paradigm have been vigorously pursued by plant biologists given that such details will help unlock a trove of new strategies for improved plant health .
From countering crop pest damage to engineering more robust global food webs , such information is valuable for ensuring sustainable and reliable yields .
Now , researchers at the University of California San Diego and their colleagues have identified the first key biological switch , or receptor , that sounds an alarm in plants specifically when herbivores attack .
The discovery is described in the online publication of the Proceedings of the National Academy of Sciences .
Animals such as humans , cows and insects are heterotrophs that derive their energy either directly or indirectly through the consumption of autotrophs , such as photosynthetic plants . This basic foundation shapes biological interactions across planet Earth .
More than 30 years ago plant biologists came to understand that plants can sense an attack from herbivorous animals in a way that is distinct from damage caused by hail storms or falling tree branches .
Similar to how human immune defenses counter an attack from viruses , plants have been shown to respond to danger from plant-eating animals through an intricate immune system of receptors .
Using a method of pinpointing genetic variants , called forward genetics , research led by Adam Steinbrenner , Alisa Huffaker and Eric Schmelz of UC San Diego ' s Division of Biological Sciences enabled discovery of the inceptin receptor , termed INR , in bean plants .
The receptor detects conserved plant protein fragments accidentally released as digestive products during caterpillar munching , thereby enabling plant recognition of attack .
" INR represents the first documented mechanism of a plant cell surface receptor responsible for perceiving animals ," said Schmelz , whose work was accomplished by deconstructing and leveraging the active evolutionary arms race between plants and herbivores .
" Our work provides some of the earliest defined mechanistic insights into the question of how plants recognize different attacking herbivores and activate immunity to animals . It is a fundamental question in biology that has been pursued for 30 years ."
Beyond beans , the finding raises interest in using INR , and potentially other receptors that remain to be discovered , as a way to boost defenses in essential agricultural crops .
" A key lesson is that plant perception mechanisms for herbivores can be precisely defined and moved into crops to afford enhanced protection ," said Schmelz . " We have shown one example but it ' s clear that hundreds if not thousands of opportunities exist to identify and stack key traits to enhance crop plant immunity to herbivores ."
The complete list of the study ' s authors : Adam Steinbrenner , Maria Muñoz-Amatriaín , Antonio Chaparro , Jessica Montserrat Aguilar Venegas , Sassoum Lo , Satohiro Okuda , Gaetan Glauser , Julien Dongiovanni , Da Shi , Marlo Hall , Daniel Crubaugh , Nicholas Holton , Cyril Zipfel , Ruben Abagyan , Ted Turlings , Timothy Close , Alisa Huffaker and Eric Schmelz
Journal Reference
1 . Adam D . Steinbrenner , Maria Muñoz-Amatriaín , Antonio F . Chaparro , Jessica Montserrat Aguilar- Venegas , Sassoum Lo , Satohiro Okuda , Gaetan Glauser , Julien Dongiovanni , Da Shi , Marlo Hall , Daniel Crubaugh , Nicholas Holton , Cyril Zipfel , Ruben Abagyan , Ted C . J . Turlings , Timothy J . Close , Alisa Huffaker , Eric A . Schmelz . A receptor-like protein mediates plant immune responses to herbivore-associated molecular patterns . Proceedings of the National Academy of Sciences , 2020 ; 202018415 DOI : 10.1073 / pnas . 2018415117
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