Comparative transcriptome analyses provide novel insights into the differential response of Pigeonpea (Cajanus cajan L.) and its wild relative (Cajanus platycarpus (Benth.) Maesen) to herbivory by Helicoverpa armigera (Hübner)
Deeper insights into the resistance response of Cajanus platycarpus were obtained based on comparative transcriptomics under Helicoverpa armigera infestation.
Devastation by pod borer, Helicoverpa armigera is one of the major factors for stagnated productivity in Pigeonpea. Despite possessing a multitude of desirable traits including pod borer resistance, wild relatives of Cajanus spp. have remained under-utilized due to linkage drag and cross-incompatibility. Discovery and deployment of genes from them can provide means to tackle key pests like H. armigera. Transcriptomic differences between Cajanus platycarpus and Cajanus cajan during different time points (0, 18, 38, 96 h) of pod borer infestation were elucidated in this study. For the first ever time, we demonstrated captivating variations in their response; C. platycarpus apparently being reasonably agile with effectual transcriptomic reprogramming to deter the insect. Deeper insights into the differential response were obtained by identification of significant GO-terms related to herbivory followed by combined KEGG and ontology analyses. C. platycarpus portrayed a multilevel response with cardinal involvement of SAR, redox homeostasis and reconfiguration of primary metabolites leading to a comprehensive defense response. The credibility of RNA-seq analyses was ascertained by transient expression of selected putative insect resistance genes from C. platycarpus viz., chitinase (CHI4), Alpha-amylase/subtilisin inhibitor (IAAS) and Flavonoid 3_5 hydroxylase (C75A1) in Nicotiana benthamiana followed by efficacy analysis against H. armigera. qPCR validated results of the study provided innovative insights and useful leads for development of durable pod borer resistance.
KeywordsHelicoverpa armigera Pigeonpea wild relatives Insect resistance RNA seq Cajanus spp.
R.S., and U.R., conceptualized the work and designed experiments. M.R. designed and conducted in planta challenging experiments. P.M. conducted the expression analyses. M.R., P.M., and A.M. analysed the data. R.S., and M.R. wrote the draft manuscript. R.S., U.R., and N.K.S. critically edited the manuscript. All the authors have read and approved the final manuscript.
The authors acknowledge financial supported by DBT-Indo Swiss Collaboration in Biotechnology (BT/IC-2/ISCB/Phase IV/01/Pigeon Pea/2015).
Compliance with ethical standards
Conflict of interest
The authors declare no conflict of interest.
- Blank LM, Leathers CR (1963) Environmental and other factors influencing development of south western cotton rust (Puccinia stakmanii). Phytopathol 53:921–928Google Scholar
- Chitti BG, Sharma HC, Madhumati T, Raghavaiah G, Krishna MKVM, Rao VS (2014) A semi-synthetic chickpea flour based diet for long-term maintenance of laboratory culture of Helicoverpa armigera. Indian J Entomol 76:336–340Google Scholar
- Grene R (2002) Oxidative stress and acclimation mechanisms in plants. The Arabidopsis Book/American Society of Plant Biologists. https://doi.org/10.1199/tab.0036.1
- Khoury CK, Castañeda-Alvarez NP, Achicanoy HA, Sosa CC, Bernau V, Kassa MT, Norton SL, van der Maesen LJG, Upadhyaya HD, Ramírez-Villegas J, Jarvis A (2015) Crop wild relatives of pigeonpea [Cajanus cajan (L.) Millsp.]: distributions, ex situ conservation status, and potential genetic resources for abiotic stress tolerance. Biol Conserv 184:259–270CrossRefGoogle Scholar
- Mallikarjuna N, Jadhav D, Reddy MV, Dutta-Tawar U (2005) Introgression of Phytophthora blight disease resistance from Cajanus platycarpus into short duration pigeonpea [Cajanus cajan (L.) Millsp.]. Ind J Genet Plant Breed 65:261–263Google Scholar
- Mishra P, Singh S, Rathinam M, Nandiganti M, Ram Kumar N, Thangaraj A, Thimmegowda V, Krishnan V, Mishra V, Jain N, Rai V (2017) Comparative proteomic and nutritional composition analysis of independent transgenic pigeon pea seeds harboring cry1AcF and cry2Aa genes and their nontransgenic counterparts. J Agric Food Chem 65:1395–1400CrossRefGoogle Scholar
- The DESeq package. https://bioconductor.org/packages/release/bioc/vignettes/DESeq/inst/doc/DESeq.pdf Accessed 17 January 2019
- Rani DS, Kumar SP, Venkatesh MN, Sri CNS, Kumar KA (2018) Bio efficacy of insecticides against gram pod borer, Helicoverpa armigera in Redgram. J Entomol Zool Stud 6:3173–3176Google Scholar
- Reddy MV, Sheila VK, Murthy AK, Padma N (1995) Mechanism of resistance to Aceria cajani in pigeonpea. Int J Trop Plant Dis 13:51–57Google Scholar
- Rhoades DF, Cates RG (1976) Towards a general theory of plant antiherbivore chemistry. Biochemical interaction between plants and insects. Recent Adv Phytochem 10:168–713Google Scholar
- Singh S, Kumar NR, Maniraj R, Lakshmikanth R, Rao KYS, Muralimohan N, Arulprakash T, Karthik K, Shashibhushan NB, Vinutha T, Pattanayak D (2018) Expression of Cry2Aa, a Bacillus thuringiensis insecticidal protein in transgenic pigeon pea confers resistance to gram pod borer. Helicoverpa armigera. Sci Rep 8:8820CrossRefGoogle Scholar
- Sujana G, Sharma HC, Manohar Rao D (2008) Antixenosis and antibiosis components of resistance to pod borer Helicoverpa armigera in wild relatives of pigeonpea. Int J Trop Insect Sci 28:191–200Google Scholar
- Zhou S, Lou YR, Tzin V, Jander G (2015) Alteration of plant primary metabolism in response to insect herbivory. Plant Physiol 169:1488–1498Google Scholar