Root-knot nematode resistance in Gossypium hirsutum L. determined by a constitutive defense-response transcriptional program

Authors: ODILON ODJEDA-RIVERA, JONATHAN - Texas Tech University; Ulloa, Mauricio; ROBERTS, PHILIP - University Of California; KOTTAPALLI, PRATIBHA - Texas Tech University; WANG, CONGLI - University Of California; Payton, Paxton; LOPEZ-ARREDONDO, DAMAR - Texas Tech University; HERRERA-ESTRELLA, LUIS - Texas Tech University

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/9/2022
Publication Date: 4/13/2022
Citation: Odilon Odjeda-Rivera, J., Ulloa, M., Roberts, P., Kottapalli, P., Wang, C., Payton, P.R., Lopez-Arredondo, D., Herrera-Estrella, L. 2022. Root-knot nematode resistance in Gossypium hirsutum L. determined by a constitutive defense-response transcriptional program. Frontiers in Plant Science. 13. https://doi.org/10.3389/fpls.2022.858313.
DOI: https://doi.org/10.3389/fpls.2022.858313

Interpretive Summary: The southern Root-Knot Nematode (RKN) is a parasitic round-worm that causes significant damage to a large number of crops, including cotton, and is a constant threat to cotton production in the United States and world-wide. Although possible, chemical control of RKN is expensive and can be unreliable. Thus, developing resistant varieties through the identification of resistance mechanisms and conventional breeding is crucial and the most economically viable approach to create new varieties with RKN resistance. In this study, ARS scientists with university cooperators investigated the mechanisms of RKN resistance in cotton varieties with different levels of resistance to RKN infection. This study identified several new candidates and mechanisms for RKN resistance in cotton and might facilitate introduction of RKN-resistance into valuable commercial varieties of cotton.

Technical Abstract: Cotton (Gossypium spp.) is the most important renewable source of natural textile fiber and one of the most cultivated crops around the world. Plant-parasitic nematode infestations, such as the southern Root-Knot Nematode (RKN), Meloidogyne incognita, represent a threat to cotton production worldwide. Host-plant resistance is a highly effective strategy to manage RKN, however, the underlying molecular mechanisms of RKN resistance remain largely unknown. In this study, we examined the differences in RKN-resistance among susceptible (Acala SJ-2; SJ2), moderately resistant (Upland Wild Mexico Jack Jones; WMJJ), and resistant (Acala NemX) cotton cultivars, using a genome-wide comparative root-transcriptome analysis (RNA-seq) in response to RKN infestation. RNA-seq data suggests that RKN-resistance is promoted by a constitutive primed-like state of defense transcriptional behavior that prevails in the roots of the NemX cultivar. Gene ontology and protein homology analyses indicate that the root transcriptional landscape is enriched in responses related to jasmonic and salicylic acid, two key phytohormones involved in plant defense responses, and constitutively activated in NemX. We show that the expression of cotton genes coding for disease resistance and receptor proteins linked to RKN-resistance and perception in plants, is also enhanced in the roots of RKN-resistant NemX. Additionally, members of these gene families are in the confidence interval of a previously identified QTL associated with RKN resistance, represent promising candidates that might facilitate introduction of RKN-resistance into commercial cotton varieties. This study provides novel insights into the molecular mechanisms that underlie RKN resistance in cotton.