The bacterium, Xanthomonas oryzae pv. oryzae, causes a bacterial blight infection in rice,  one of the most economically important crops in India. This infection is fatal for rice crops,  and farmers can lose up to 60% of their crops owing to this disease.  

 

The first barrier encountered by the bacterium when it comes in contact with the rice plant  is the cell‐ wall of the plant cells, which confers structural integrity and protection to the  cell. In order to breakdown the cell wall, Xanthomonas secretes certain cell‐wall degrading  enzymes. This is sensed by the plant which then activates its innate immune responses to  fight the bacterium. But the bacterium has also evolved to secrete specialized proteins  (called the effector proteins) that can suppress the plant immune responses. It is the  balance between the two that decides if the plant succeeds to protect itself from the  bacterial attack.

 

 

 

Dr.  Ramesh  V.  Sonti,  at  CSIR‐  Centre  for  Cellular  and  Molecular  Biology  (CSIR‐CCMB),  Hyderabad, along with senior scientist Dr. Hitendra K. Patel and research scholar Ms. Sohini  Deb, have studied the interplay of the interactions of these effector molecules and their role  in the rice plant. The team has identified the principal players behind this process and  discovered a new plant‐bacterial interaction which renders the plant to be resistant to  bacterial  infection.  They  found  that  a  bacterial  effector,  named  XopQ,  suppresses  rice  immune responses by interacting with certain members of a class of proteins in the rice  plant cells, known as the 14‐3‐3 proteins. In an interesting experiment, they altered the  sequence of the effector protein at one particular position. Consequently, they found that  this mutant form of the bacterial effector protein, is now unable to suppress the plant  immune responses. Instead it makes the plant resistant to bacterial infection, by interaction  with another different 14‐3‐3 protein.   Understanding the molecular players in plant immune response pathway offers new ways of  blocking the bacterial hijack as well as strengthening the defence responses of the plant  cells. Findings of the study have been published in the Journal Molecular Plant Pathology, a  publication of the British Society for Plant Pathology.

 

***

(रिलीज़ आईडी: 1572281) आगंतुक पटल : 167