|VARSANI, SURESH - University Of Nebraska|
|BASU, SAUMIK - University Of Nebraska|
|FELTON, GARY - Pennsylvania State University|
|LUTHE, DAWN - Pennsylvania State University|
|LOUIS, JOE - Pennsylvania State University|
Submitted to: Plant Signaling and Behavior
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/8/2016
Publication Date: 7/28/2016
Citation: Varsani, S., Basu, S., Williams, W.P., Felton, G., Luthe, D., Louis, J. 2016. Intraplant communication in maize contributes to defense against insects. Plant Signaling and Behavior. 11(8):1559-2324. http://dx.doi.org/10.1080/15592324.2016.1212800.
Interpretive Summary: A unique protein, a papain-like protease, was identified in corn germplasm lines Mp704 and Mp708 that were developed and released by USDA-ARS at Mississippi State as sources of resistance to fall armyworm and southwestern corn borer. The protein was also found to function as a phloem-mobile protein that curtails growth of the sap-sucking corn leaf aphid. The current study examined whether above-ground feeding by corn leaf aphid induces accumulation of the protein in the plant’s roots and whether this in turn enhances resistance to the root-feeding western corn root worm. The results indicated that resistance to western corn root worm was enhanced by accumulation of the protein in the roots. These results indicate that germplasm lines such as Mp708 can be used in breeding for resistance to a variety of important insect pests.
Technical Abstract: The vasculature of plants act as a channel for transport of signal(s) that facilitate long-distance intraplant communication. In maize, Maize insect resistance1-Cysteine Protease (Mir1-CP), which has homology to papain-like proteases, provides defense to different feeding guilds of insect pests. Furthermore, accumulation of Mir1-CP in the vasculature suggests that Mir1-CP can potentially function as a phloem-mobile protein. In a recent study, we provided evidence that Mir1-CP can curtail the growth of phloem-sap sucking insect, corn leaf aphid (CLA; Rhopalosiphum maidis). Our current study further examined whether aboveground feeding by CLA can induce resistance to subsequent herbivory by belowground feeding western corn rootworm (WCR; Diabrotica virgifera virgifera). Aboveground feeding by CLA systemically induced the accumulation of Mir1-CP in the roots. Furthermore, foliage feeding by CLA provided enhanced resistance to subsequent herbivory by belowground feeding of WCR. Taken together, our previous findings and results presented here indicate that long-distance transport of Mir1-CP is critical for providing enhanced resistance to insect attack in maize.