Some compatible Rhizobium leguminosarum strains in peas decrease infections when parasitised by Orobanche crenata

Abstract

Orobanche crenata (crenate broomrape) produces serious damage to many legume crops and particularly becomes a limiting factor for pea production in the Mediterranean basin. Nodulation effects on pea-broomrape relationships were studied using the commercial pea cultivar Douce de Provence and different Rhizobium strains using pot and Petri dish experiments. First, the benefit of bacterial inoculation on plant growth and efficiency of N incorporation were demonstrated for two isolates, P.SOM and P.1236. These isolates did not influence parasite germination induced by the artificial stimulant, GR24. In contrast, pea root inoculation with P.SOM and P.1236 isolates led to a reduced root infection by O. crenata, resulting from a lower Orobanche germination rate close to pea roots and a limited capacity of the parasitic seedlings to develop tubercles. Broomrape necrosis was observed both before and after parasite attachment to inoculated pea roots. Concomitantly, reduction in infection was accompanied by enhanced peroxidase activity and constantly high phenylalanine ammonia lyase activity in pea roots. These data suggest the involvement of these enzymes in pea resistance to crenate broomrape induced by the compatible rhizobia. Management of Orobanche via crop selection based on these enzyme systems is a viable option. Keywords: biocontrol, legumes, peroxidase, phenylalanine ammonia lyase. MABROUK Y, ZOURGUI L, SIFI B, DELAVAULT P, SIMIER P, BELHADJ O (2007) Some compatible Rhizobium leguminosarum strains in peas decrease infections when parasitised by Orobanche crenata. Weed Research 47, 44-53.

Development of Mesorhizobium ciceri-Based Biofilms and Analyses of Their Antifungal and Plant Growth Promoting Activity in Chickpea Challenged by Fusarium Wilt

“…This suggests that biofilms are much efficient in elicitation of induced systemic resistance in plants thereby, reducing disease incidence. Similar type of increase in defense enzyme activity has been reported by Mabrouk et al [22] and Dutta et al [62] in pea and pigeon pea against fusarial wilt. Osdaghi et al [23] also reported induction of resistance in common bean when bacterized with Rhizobium leguminosarum bv.…”

“…Potential mechanisms include mycoparasitism, competition for nutrients, production of antifungal metabolites like hydrogen cyanide (HCN), antibiotics, siderophore and induction of plant defense mechanisms [18][19][20]. A number of studies showed higher elicitation of enzymes like L-phenylalanine ammonia lyase (PAL), peroxidase (POX) and polyphenol oxidase (PPO) in plants pretreated with rhizobial strains, which play a significant role in induction of systemic resistance against several phytopathogens [21][22][23]. Rhizobia can effectively form biofilm with common soil fungi [6].…”

Response of some chickpea (Cicer arietinum L.) genotypes to Orobanche foetida Poir. parasitism

“…foetida (Bouraoui et al, 2012) and the pathosystem pea/O. crenata (Mabrouk et al, 2007). The infection rate reduction was explained by the decrease of the parasite seeds germination stimulation and/or by the presence of necrosis before or after tubercle attachment.…”

Integrated Pest Management in Chickpea

“…In parallel, the nodulated roots displayed high Lox activity related to the overexpression of the lox1 gene. Similarly, the expression of phenylalanine ammonia lyase (PAL) and 6a-hydroxymaackiain 3-O-methyltransferase (Hmm6a) genes were induced early during nodule development, suggesting the central role of the phenylpropanoid/isoflavonoid pathways in the elicited defence (Mabrouk et al, 2007b(Mabrouk et al, , 2007c(Mabrouk et al, , 2010.…”