植物体内的茉莉酸可有效抗虫

Plants can't swat（重拍，猛击） a bug¹ or run away from one, but that doesn't mean that plants can't fight back. Plants have evolved unique and sophisticated immune systems to defend themselves against insects and pathogens. Plant hormones² called jasmonates（茉莉酸类） play an important role in this defense³, but jasmonates have been found to also be important for plant growth. Now, researchers reporting in the May 23 issue of the Cell Press journal Molecular⁴ Cell have discovered a gene⁵ in the jasmonate pathway that controls plant defenses but does not play a detectable⁶ role in plant development. These findings could be applied⁷ to improve crop resistance in agriculture. "Our findings may be used to develop a novel strategy to engineer dual⁸ plant resistances against both insects and pathogens in the agricultural industry by manipulating the jasmonate signaling pathway without negatively affecting plant growth," says senior author Dr. Daoxin Xie of Tsinghua University in Beijing, China.

 

Dr. Xie and his colleagues performed genetic⁹ screening tests in plants to silence different genes¹⁰ in the jasmonate pathway. The experiments revealed that silencing the JAV1 gene significantly enhanced jasmonate-regulated defense responses against pathogens and insects but did not severely¹² alter jasmonate-mediated developmental processes.

 

The researchers also found that in normal plants, jasmonates, which accumulate following an attack by insects or pathogens, trigger the degradation¹³ of the protein encoded by the JAV1 gene. Without the JAV1 protein to keep them in check, other regulators are free to turn on immune response genes that rev¹¹ up the immune system.

 

"These findings have provided an insight into the molecular mechanism¹⁴ by which plants integrate jasmonate signals to protect themselves from insect attack and pathogen infection," the authors write.

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