Galls from Calliandra brevipes BENTH (Fabaceae : Mimosoidae): evidence of apyrase activity contribution in a plant - insect interaction

Abstract

By western blots, cross-immunoreactivity with polyclonal anti-potato apyrase antibodies identified the Calliandra brevipes apyrase as a band of 75 kDa in the tissues of non-galled stem and leaves, and those of globose galls. The non-galled tissues hydrolysed either ATP, ADP, UDP, GTP or GDP. In globose galls, ADP, UDP and GDP hydrolysis were 1.7–5.1-fold higher than in non-galled tissues. ADP and UDP hydrolysis either from non-galled or globose gall tissues were 10–38% stimulated by 5 mM calcium, and drastically reduced (66–99%) by the addition of 5 mM EDTA or EGTA, confirming the divalent cation dependence. Nucleotidase, phosphatase or ATPase activities contributed in lower reaction rates. Apyrase activity was confirmed in C. brevipes tissues by nondenaturing polyacrylamide gel electrophoresis and western blots. By histochemical techniques, the ADPase activity was found as a granular-dense lead phosphate deposit homogeneously distributed at the external surface, and inside the nutritive cells of the globose gall. The sites of polyclonal anti-potato apyrase antibodies corroborate these localisations. The globose galls of the C. brevipes stems increase their capacity of hydrolysing nucleotides, which could be associated with carbohydrate biosynthesis, signalling and/or cell proliferation, crucial for feeding and survival of the insect.

Role of Ca2+ in Mediating Plant Responses to Extracellular ATP and ADP

“…Interestingly, this ectopapyrase appears to be the target of elicitor and suppressor molecules secreted by the fungus. Extracellular ATP and the ectoapyrases that hydrolyze eATP also appear to be a battleground between plants and insects during defense responses [ 100 , 101 , 102 ].…”

Gall-Inducing Parasites: Convergent and Conserved Strategies of Plant Manipulation by Insects and Nematodes

“…A follow-up study revealed that a protein highly abundant in Hessian fly larval salivary glands, the nucleoside diphosphate kinase (NDK), was indeed injected into host tissues during feeding (137). Apyrase activity levels are also higher in Calliandra brevipes galls than in non-galled tissues, suggesting a key role for this early signaling disruptor (together with other molecules) in the plant reprogramming induced by plant-manipulating insects (35). Interestingly, PRXs have been detected in the salivary secretions of several insects and have been shown to be required for successful M. incognita development (38).…”

Extracellular ATP acts as a damage-associated molecular pattern (DAMP) signal in plants

“…A clear mechanism for this response would be that the salivary apyrases dampen wound-released ATP to restrict the plant defense response. Furthermore, a higher catalytic activity of apyrases was detected in globose insect galls on Calliandra brevipes ( Detoni et al, 2012 ). Similar mechanisms for controlling extracellular ATP concentrations are observed in the interactions between animals and parasitic worms or blood sucking insects ( Valenzuela et al, 2001 ; Da’dara et al, 2014 ).…”