capsici resulted in the purification of a phytotoxic protein fraction designated as p47f, capable of inducing wilting and necrosis on leaves of Capsicum chinense Jacq, and having a 47 kDa polypeptide with proteolytic activity as
the major component. The isolated p47f fraction induced DNA degradation and decreased cell survival of C. chinense cell suspension culture. Sequencing of p47f indicated the presence of 15 proteins, which could be grouped into seven classes including a protease group, cell wall remodelling proteins and the transglutaminase elicitor M81D, among others. This is the first report of P. capsici secreting proteins that modulate cell responses mediated by ROS in the host. “
“The effect of seed-borne pathogens of wheat and barley on crown and root rot diseases of seven barley cultivars (Jimah-6, Jimah-51, Jimah-54, Jimah-58, Omani, Beecher and Duraqi) and three wheat cultivars (Cooley, Maissani and Shawarir) BTK inhibitor was investigated. Bipolaris sorokiniana and Alternaria alternata were detected in seeds of at least eight cultivars, but Fusarium species in seeds of only two barley cultivars (Jimah-54 and Jimah-58). Crown rot and root rot symptoms developed on barley BYL719 ic50 and wheat cultivars following germination of infected seeds in sterilized growing media. Bipolaris sorokiniana was the only pathogen consistently isolated from crowns and roots of the emerging seedlings. In
addition, crown rot and root rot diseases of non-inoculated barley cultivars correlated significantly with B. sorokiniana inoculum in seeds (P = 0.0019), but not with Fusarium or Alternaria (P > 0.05). These results indicate the role of seed-borne inoculum of B. sorokiniana in development of crown rot and root rot diseases. Pathogenicity tests of B. sorokiniana isolates confirmed its role in inducing crown rot and root rot, with two wheat cultivars being more resistant to crown and root rots than most barley
cultivars (P < 0.05). Barley cultivars also exhibited significant differences in resistance to crown rot (P < 0.05). In addition, black point Unoprostone disease symptoms were observed on seeds of three barley cultivars and were found to significantly affect seed germination and growth of some of these cultivars. This study confirms the role of seed-borne inoculum of B. sorokiniana in crown and root rots of wheat and barley and is the first report in Oman of the association of B. sorokiniana with black point disease of barley. “
“The infection of wheat spikelets by Bipolaris sorokiniana, the causal agent of black point on grains and grain shrivelling, was examined by light and electron microscopy. Conidia of the pathogen germinated 6–12 h after inoculation on the surfaces of the different spike tissues. Extracellular sheaths were observed on germ tubes and appressoria attached to the surfaces of lemma, palea and seeds, but were only scarcely detected on the surface of conidia.