Natural Variation in Maize Defense against Insect Herbivores

Meihls, Lisa N.; Kaur, Harleen; Jander, Georg

doi:10.1101/sqb.2012.77.014662

Cited by 91 publications

(93 citation statements)

References 146 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For instance, other QTL may function in maize inbred lines that are more resistant to R. maidis than B73 (Figure 2A). Similarly, genetic mapping of resistance to chewing herbivores has identified QTL that are not linked to known benzoxazinoid-related genes (McMullen et al, 2009a;Meihls et al, 2012). Our results demonstrate that newly available maize genetic and genomic resources make it straightforward to proceed from the observation of such natural variation in insect resistance to elucidating the genetic and biochemical basis of this variation.…”

Section: Discussionmentioning

confidence: 99%

“…As chewing herbivores rather than aphids have been the focus of most prior research on natural variation in maize herbivore resistance (McMullen et al, 2009a;Meihls et al, 2012), we initiated experiments using R. maidis and recombinant inbred lines of the NAM population to identify resistance mechanisms. Concerted mapping of loci associated with aphid resistance, benzoxazinoid production, and callose deposition was followed by the molecular and biochemical characterization of candidate genes.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Natural Variation in Maize Aphid Resistance Is Associated with 2,4-Dihydroxy-7-Methoxy-1,4-Benzoxazin-3-One Glucoside Methyltransferase Activity

et al. 2013

View full text Add to dashboard Cite

Plants differ greatly in their susceptibility to insect herbivory, suggesting both local adaptation and resistance tradeoffs. We used maize (Zea mays) recombinant inbred lines to map a quantitative trait locus (QTL) for the maize leaf aphid (Rhopalosiphum maidis) susceptibility to maize Chromosome 1. Phytochemical analysis revealed that the same locus was also associated with high levels of 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one glucoside (HDMBOA-Glc) and low levels of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one glucoside (DIMBOA-Glc). In vitro enzyme assays with candidate genes from the region of the QTL identified three O-methyltransferases (Bx10a-c) that convert DIMBOA-Glc to HDMBOA-Glc. Variation in HDMBOA-Glc production was attributed to a natural CACTA family transposon insertion that inactivates Bx10c in maize lines with low HDMBOA-Glc accumulation. When tested with a population of 26 diverse maize inbred lines, R. maidis produced more progeny on those with high HDMBOA-Glc and low DIMBOA-Glc. Although HDMBOA-Glc was more toxic to R. maidis than DIMBOA-Glc in vitro, BX10c activity and the resulting decline of DIMBOA-Glc upon methylation to HDMBOA-Glc were associated with reduced callose deposition as an aphid defense response in vivo. Thus, a natural transposon insertion appears to mediate an ecologically relevant trade-off between the direct toxicity and defense-inducing properties of maize benzoxazinoids.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Natural Variation in Maize Aphid Resistance Is Associated with 2,4-Dihydroxy-7-Methoxy-1,4-Benzoxazin-3-One Glucoside Methyltransferase Activity

et al. 2013

View full text Add to dashboard Cite

show abstract

“…At the same time, maize is highly confounded by insect pests that can dramatically decrease yields, and there is extensive variation of resistance in this crop against insect pests (McMullen et al, 2009;Meihls et al, 2012). Different feeding guilds of insect pests cause aboveground and belowground damage to the maize crop.…”

mentioning

confidence: 99%

Ethylene Contributes to maize insect resistance1-Mediated Maize Defense against the Phloem Sap-Sucking Corn Leaf Aphid

et al. 2015

View full text Add to dashboard Cite

ORCID IDs: 0000-0001-7137-8797 (J.L.); 0000-0002-3904-6984 (S.B.); 0000-0003-3192-978X (S.V.); 0000-0002-3550-5522 (V.J.); 0000-0001-9147-3871 (W.P.W.).Signaling networks among multiple phytohormones fine-tune plant defense responses to insect herbivore attack. Previously, it was reported that the synergistic combination of ethylene (ET) and jasmonic acid (JA) was required for accumulation of the maize insect resistance1 (mir1) gene product, a cysteine (Cys) proteinase that is a key defensive protein against chewing insect pests in maize (Zea mays). However, this study suggests that mir1-mediated resistance to corn leaf aphid (CLA; Rhopalosiphum maidis), a phloem sap-sucking insect pest, is independent of JA but regulated by the ET-signaling pathway. Feeding by CLA triggers the rapid accumulation of mir1 transcripts in the resistant maize genotype, Mp708. Furthermore, Mp708 provided elevated levels of antibiosis (limits aphid population)-and antixenosis (deters aphid settling)-mediated resistance to CLA compared with B73 and Tx601 maize susceptible inbred lines. Synthetic diet aphid feeding trial bioassays with recombinant Mir1-Cys Protease demonstrates that Mir1-Cys Protease provides direct toxicity to CLA. Furthermore, foliar feeding by CLA rapidly sends defensive signal(s) to the roots that trigger belowground accumulation of the mir1, signifying a potential role of long-distance signaling in maize defense against the phloem-feeding insects. Collectively, our data indicate that ET-regulated mir1 transcript accumulation, uncoupled from JA, contributed to heightened resistance to CLA in maize. In addition, our results underscore the significance of ET acting as a central node in regulating mir1 expression to different feeding guilds of insect herbivores.

show abstract

“…Indirect damage comes from the fact that the corn leaf aphid is the most effective vector of several plant viruses, including Maize yellow dwarf virus and Barley yellow dwarf virus, which are among the most economically important diseases of cereal crops and forage grasses (El-Muadhidi et al, 2001;Hawkes and Jones, 2005;Power et al, 2011;Jarošová et al, 2013;Krueger et al, 2013). As protection against aphids and other insect pests, maize plants implement not only constitutive defenses but also inducible responses that require broad shifts in gene expression and biochemical pathways (Thompson and Goggin, 2006;Meihls et al, 2012).…”

mentioning

confidence: 99%

Dynamic maize responses to aphid feeding are revealed by a time series of transcriptomic and metabolomic assays

et al. 2015

View full text Add to dashboard Cite

(A.H.); 0000-0002-9675-934X (G.J.).As a response to insect attack, maize (Zea mays) has inducible defenses that involve large changes in gene expression and metabolism. Piercing/sucking insects such as corn leaf aphid (Rhopalosiphum maidis) cause direct damage by acquiring phloem nutrients as well as indirect damage through the transmission of plant viruses. To elucidate the metabolic processes and gene expression changes involved in maize responses to aphid attack, leaves of inbred line B73 were infested with corn leaf aphids for 2 to 96 h. Analysis of infested maize leaves showed two distinct response phases, with the most significant transcriptional and metabolic changes occurring in the first few hours after the initiation of aphid feeding. After 4 d, both gene expression and metabolite profiles of aphid-infested maize reverted to being more similar to those of control plants. Although there was a predominant effect of salicylic acid regulation, gene expression changes also indicated prolonged induction of oxylipins, although not necessarily jasmonic acid, in aphid-infested maize. The role of specific metabolic pathways was confirmed using Dissociator transposon insertions in maize inbred line W22. Mutations in three benzoxazinoid biosynthesis genes, Bx1, Bx2, and Bx6, increased aphid reproduction. In contrast, progeny production was greatly decreased by a transposon insertion in the single W22 homolog of the previously uncharacterized B73 terpene synthases TPS2 and TPS3. Together, these results show that maize leaves shift to implementation of physical and chemical defenses within hours after the initiation of aphid feeding and that the production of specific metabolites can have major effects in maize-aphid interactions.

show abstract

Natural Variation in Maize Defense against Insect Herbivores

Cited by 91 publications

References 146 publications

Natural Variation in Maize Aphid Resistance Is Associated with 2,4-Dihydroxy-7-Methoxy-1,4-Benzoxazin-3-One Glucoside Methyltransferase Activity

Natural Variation in Maize Aphid Resistance Is Associated with 2,4-Dihydroxy-7-Methoxy-1,4-Benzoxazin-3-One Glucoside Methyltransferase Activity

Ethylene Contributes to maize insect resistance1-Mediated Maize Defense against the Phloem Sap-Sucking Corn Leaf Aphid

Dynamic maize responses to aphid feeding are revealed by a time series of transcriptomic and metabolomic assays

Contact Info

Product

Resources

About