Plant resistance to parasitic plants: molecular approaches to an old foe

Abstract

SummaryParasitic weeds pose severe constraint on major agricultural crops. Varying levels of resistance have been identified and exploited in the breeding programmes of several crops. However, the level of protection achieved to date is either incomplete or ephemeral. Resistance is mainly determined by the coexistence of several mechanisms controlled by multigenic and quantitative systems. Efficient control of the parasite requires a better understanding of the interaction and their associated resistance mechanisms at the histological, genetic and molecular levels. Application of postgenomic technologies and the use of model plants should improve the understanding of the plant-parasitic plant interaction and drive not only breeding programmes through either marker-assisted selection (MAS) or transgenesis but also the development of alternative methods to control the parasite. This review presents the current approaches targeting the characterization of resistance mechanisms and explores their potentiality to control parasitic plants.New Phytologist (2007) 173 : 703-712

Interspecific RNA Interference of SHOOT MERISTEMLESS-Like Disrupts Cuscuta pentagona Plant Parasitism

“…To date there is no single dodder control strategy available that is both effective and sustainable; thus, spread of the parasite continues unabated (Rispail et al, 2007). Strategies for dodder management include crop rotation, flooding or flaming some perennial crops, tilling, timing of crop planting, and use of selective herbicides (Mishra, 2009;Nadler-Hassar et al, 2009;Sandler, 2010).…”

Striga

“…The development of molecular markers associated with resistance to Striga has offered a promising way to rapidly accumulate several resistance genes since conventional breeding has shown to be time-consuming, largely if not completely dependent on climatic and environmental conditions, and therefore less effective (Ejeta and Gressel, 2007;Rispail et al, 2007). It is interesting to note that in the most studied millet crops, sorghum and pearl millet, potential resistance phenotypes have been identified in wild relatives.…”

“…The combination of genetic mapping and gene expression studies should provide an integrated approach to pave the knowledge gap in millets, especially pearl millet and small millets. Moreover, comparative genomics can point to important resistance genes in the understudied millet crops as they are discovered in other millet crops like sorghum (Michelmore, 2000;Rispail et al, 2007).…”

“…Thanks to the recent emergence of biotechnology techniques and genomic resources, the potential of artificial resistance in host plants makes the genetic engineering a viable strategy in this context. Indeed, studies aimed at the molecular characterization of the host plant -parasite interaction and host resistance through expression analysis of the genes, proteins and metabolites involved in these processes, are the subject of increasing interest and offer weed researchers the opportunity for deploying genetic transformation tools to enhance the control of the parasitic plants (Rispail et al, 2007;Aly, 2012). With the great initiative of the parasitic plant genome project' (http://ppgp.huck.psu.edu/) (Westwood et al, 2012), genetic resistance based on silencing of a target gene in the host plant is now feasible.…”

“…Millets thus play a critical role in ensuring food security in these regions Senthilvel et al, 2008 (Gurney et al, 2003(Gurney et al, , 2006Elzein and Kroschel, 2004;Vasey et al, 2005;Amusan et al, 2008). Indeed, Striga are the major and persistent biotic threat to production of these crops mostly grown on the hottest and driest marginal regions of sub-Saharan Africa, Middle East and large part of Asia (Gurney et al, 2002;Gressel et al, 2004;Ejeta, 2007;Rispail et al, 2007;Scholes and Press, 2008;Parker, 2012). At present, over 50 million ha of the arable farmland under cereals in sub-Saharan Africa are infested by Striga.…”