The mitogen‐activated protein kinases WIPK and SIPK regulate the levels of jasmonic and salicylic acids in wounded tobacco plants

Abstract

SummaryIn tobacco (Nicotiana tabacum), wounding causes rapid activation of two mitogen-activated protein kinases (MAPKs), wound-induced protein kinase (WIPK) and salicylic acid (SA)-induced protein kinase (SIPK), and the subsequent accumulation of jasmonic acid (JA). Our previous studies suggested that activation of WIPK is required for the production of wound-induced JA. However, the exact role of WIPK remains unresolved. We generated transgenic tobacco plants in which either WIPK or SIPK were silenced using RNA interference to define the roles of WIPK and SIPK in the wound response. In addition, transgenic tobacco plants were generated in which both WIPK and SIPK were silenced to examine the possibility that they have redundant roles. Wound-induced JA production was reduced compared with non-silenced plants in all of the WIPK-, SIPKand WIPK/SIPK-silenced plants. Transgenic plants over-expressing NtMKP1, a gene encoding tobacco MAPK phosphatase, which inactivates WIPK and SIPK, also exhibited reduced JA production in response to wounding. In both WIPK/SIPK-silenced and NtMKP1-over-expressing plants, wounding resulted in an abnormal accumulation of both SA and transcripts for SA-responsive genes. These results suggest that WIPK and SIPK play an important role in JA production in response to wounding, and that they function cooperatively to control SA biosynthesis.

Tomato MAPKs LeMPK1, LeMPK2, and LeMPK3 function in the systemin-mediated defense response against herbivorous insects

“…7). This is comparable to the reduction of ethylene synthesis in flagellintreated Arabidopsis mpk6 null mutants (27), wounded SIPKsilenced tobacco (38), and N. attenuata treated with M. sexta oral secretions (39). These data do not exclude the possibility that MPK1/2 might recruit additional cytosolic or nuclear substrates.…”

“…5A). Similarly, both different and overlapping roles in the response of Nicotiana tabacum and Nicotiana attenuata to wounding or M. sexta oral secretions were reported for SIPK and WIPK, the tobacco orthologs of tomato MPK1 and MPK3 (38,39).…”

Arabidopsis Mitogen-Activated Protein Kinase Kinases MKK1 and MKK2 Have Overlapping Functions in Defense Signaling Mediated by MEKK1, MPK4, and MKS1

“…Biotic and abiotic stress in this tobacco will activate SIPK and WIPK, orthologs of Arabidopsis MPK3 and MPK6, respectively, resulting in JA accumulation and hypersensitive responses (Yang et al, 2001). Plants in which SIPK or WIPK are silenced show reduced woundinduced JA production, and SA levels after wounding are enhanced (Seo et al, 2007). This is in contrast to the situation in Arabidopsis in which JA levels are not affected in the mutants studied here, whereas SA levels are enhanced in mkk1/2 in the unchallenged state.…”

Simultaneous activation of salicylate production and fungal resistance in transgenic Chrysanthemum producing caffeine

“…These values are comparable with those found in tobacco plants. 13 In mature leaves of the transgenic C#3, which showed the strongest …”