The ZmRCP-1 promoter of maize provides root tip specific expression of transgenes in plantain

Abstract

BackgroundBananas and plantains (Musa spp.) provide 25 % of the food energy requirements for more than 100 million people in Africa. Plant parasitic nematodes cause severe losses to the crop due to lack of control options. The sterile nature of Musa spp. hampers conventional breeding but makes the crop suitable for genetic engineering. A constitutively expressed synthetic peptide in transgenic plantain has provided resistance against nematodes. Previous work with the peptide in potato plants indicates that targeting expression to the root tip improves the efficacy of the defence mechanism. However, a promoter that will provide root tip specific expression of transgenes in a monocot plant, such as plantain, is not currently available. Here, we report the cloning and evaluation of the maize root cap-specific protein-1 (ZmRCP-1) promoter for root tip targeted expression of transgenes that provide a defence against plant parasitic nematodes in transgenic plantain.ResultsOur findings indicate that the maize ZmRCP-1 promoter delivers expression of β-glucuronidase (gusA) gene in roots but not in leaves of transgenic plantains. In mature old roots, expression of gusA gene driven by ZmRCP-1 becomes limited to the root cap. Invasion by the nematode Radopholus similis does not modify Root Cap-specific Protein-1 promoter activity.ConclusionsRoot cap-specific protein-1 promoter from maize can provide targeted expression of transgene for nematode resistance in transgenic plantain.

Recombinant expression of osmotin in barley improves stress resistance and food safety during adverse growing conditions

“…Heterologous peptide expression can be driven by tissue specific or constitutive promoters. [37] demonstrated usage of root tip specific promoter to induce resistance to biotic stress induced by nematodes. Alternatively, constitutive promoter CaMV35S [38, 39] can be used for heterologous protein production in plants.…”

Gall-specific promoter, an alternative to the constitutive CaMV35S promoter, drives host-derived RNA interference targeting Mi-msp2 gene to confer effective nematode resistance

“…The expression of RNAi constructs under the control of their constitutive promoters serves the purpose of gene silencing, but a controlled targeting approach using the NRRS promoter will be more specific while effectively deterring PPN infection (Goddijn et al, 1993;Kakrana et al, 2017). Over the past few decades, various NRRS promoters have been found to be effectively activated in response to PPN infection, such as TobRB7, LEMMI9, Hahsp17.7G4, AtCel-1, AtWRKY23, ZmRCP-1, pAt1g74770 and pAt2g18140 (Opperman et al, 1994;Escobar et al, 1999;Escobar et al, 2003;Sukno et al, 2006;Grunewald et al, 2008;Onyango et al, 2016;Kakrana et al, 2017). These NRRS promoters can be employed to drive RNAi constructs for specific nematode target genes to dissuade PPN infection (Sukno et al, 2006;Kakrana et al, 2017).…”

“…Previously a range of NRRS promoters have been successfully identified and employed to combat PPN infection to varying degrees ( Opperman et al., 1994 ; Thurau et al, 2003 ; Sukno et al., 2006 ; Kumar et al, 2016 ). The A. thaliana promoter MDK4-20 and the Zea mays promoter ZmRCP-1 are expressed specifically in the root tip making them suitable to control the expression of the antinematode defence genes and dsRNA molecules targeting PPN genes ( Lilley et al., 2011 ; Onyango et al., 2016 ). Therefore, the study of RNAi constructs under the control of NRRS promoters will provide insights into the molecular functionality of the nematode responsive promoters as well as the mechanisms of their effector genes.…”

Identification, Validation and Utilization of Novel Nematode-Responsive Root-Specific Promoters in Arabidopsis for Inducing Host-Delivered RNAi Mediated Root-Knot Nematode Resistance

“…Similarly, the splicing factor gene driven by 35S promoter in Arabidopsis transgenic lines exhibited up to 71% reduction in gall number (Kumar et al, 2017 ). In the last few years, several promoters have been identified in various crops including tobacco (Opperman et al, 1994 ), LEMMI9 in tomato (Escobar et al, 1999 ), Hahsp17.7G4 in Helianthus annuus (Escobar et al, 2003 ), AtCel-1 in Arabidopsis (Sukno et al, 2006 ), AtWRKY23 (Grunewald et al, 2008 ), and ZmRCP-1 in maize, banana, and plantains (Onyango et al, 2016 ). None of the promoters identified have been utilized for driving the production of dsRNA of nematode genes for HD-RNAi silencing.…”