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.