The Cotton Wall-Associated Kinase GhWAK7A Mediates Responses to Fungal Wilt Pathogens by Complexing with the Chitin Sensory Receptors

Plant receptor-like kinases (RLKs) are important players in response to pathogen infections. Verticillium and Fusarium wilts, caused by Verticillium dahliae (Vd) and Fusarium oxysporum f. sp vasinfectum (Fov), respectively, are among the most devastating diseases in cotton (Gossypium spp). To understand the cotton response to these soil-borne fungal pathogens, we performed a genome-wide in silico characterization and functional screen of diverse RLKs for their involvement in cotton wilt diseases. We identified Gossypium hirsutum GhWAK7A, a wall-associated kinase, that positively regulates cotton response to both Vd and Fov infections. Chitin, the major constituent of the fungal cell wall, is perceived by lysin-motif-containing RLKs (LYKs/CERK1), leading to the activation of plant defense against fungal pathogens. A conserved chitin sensing and signaling system is present in cotton, including chitin-induced GhLYK5-GhCERK1 dimerization and phosphorylation, and contributes to cotton defense against Vd and Fov. Importantly, GhWAK7A directly interacts with both GhLYK5 and GhCERK1 and promotes chitin-induced GhLYK5-GhCERK1 dimerization. GhWAK7A phosphorylates GhLYK5, which itself does not have kinase activity, but requires phosphorylation for its function. Consequently, GhWAK7A plays a crucial role in chitin-induced responses. Thus, our data reveal GhWAK7A as an important component in cotton response to fungal wilt pathogens by complexing with the chitin receptors.     

An Ethnography of Dementia

Culture, Medicine, and Psychiatry - The experiences of dementia sufferers have rarely been examined in sociological literature. This article seeks to describe the experiences of one Alzheimer's...     

ONTOGENY AND ANATOMY OF THE FLOWER OF LIMNOCHARIS FLAVA (BUTOMACEAE)

The flowers of Limnocharis flava (L.) Buch. are borne in an indeterminate umbel and each consists of three sepals, three yellow petals, and about 18 carpels surrounded by numerous stamens and staminodia. The androecium is centrifugally developed, and the last-formed members are staminodial; it is supplied by branching vascular systems. Carpels arise almost simultaneously, and a prominent residual floral apex remains. The carpels are partially conduplicately closed and are also primitive in possessing laminar placentation and in lacking differentiation of a style. The gynoecium is essentially apocarpous, but there are slight fusions of adjacent carpels near their ventral margins where they are attached to the receptacle. It is suggested that the Limnocharis flower is the most primitive in the family.     

Nuclear matrix network in Allium cepa

The presence of a nuclear matrix network in animal cells has been claimed by many workers in the last decade. The purpose of our study was to see whether a similar structure could be identified in the cells of higher plants. Our work revealed the presence of a fibrillar nonchromatinic network in Allium cepa nuclei. This could be impregnated with AgNO₃ in intact cells as well as in isolated matrices at the light microscope level. It was seen to be associated with the chromosomes from early to late prophase and also in telophase. Ultrastructurally a fibrillar network comparable to that reported earlier from animal cells was observed. This network remained associated with metaphase and anaphase chromosomes and could be digested with pepsin. Biochemical estimation of the isolated matrix revealed it to be made up mainly of proteins (more than 90%), traces of DNA (less than 1%) and a small quantity of RNA. SDS PAGE showed three polypeptide bands in the molecular weight range of 55,000–63,000 daltons.     

Effect of nifedipine administration on the functional capacity of neutrophils

Administration of nifedipine to mice over a period of six months caused a significant (p<0.05) decrease in neutrophilic functions viz superoxide generation, coupled to NADPH oxidase activity as well as NADPH production by HMP shunt. Properties like chemotaxis and phagocytosis showed a similar decrease. From this study, it is seen that nifedipine causes neutrophil functional abrogation which is therefore an apparent concern for the prolonged usage of the drug. However, relevance of the mouse model to clinical situation needs further investigation.