Anatomical, chemical and ultrastructural characterization of secretory spines in two Cactaceae species

• Grant number: 17/14891-5
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): November 01, 2017
• Effective date (End): February 28, 2019
• Field of knowledge: Biological Sciences - Botany - Plant Morphology
• Principal Investigator: Tatiane Maria Rodrigues
• Grantee: Stefany Cristina de Melo Silva
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The occurrence of secretory spines, described as extrafloral nectars (EFNs), associated with the areoles in cladodes is a common aspect of many Cactaceae species. The presence and location of NEFs have been employed as diagnostic features for species in the family. EFNs in Cactaceae are morphologically diversified and can be highly modified spines or not, scale leaves and specialized epidermal and cortical regions located in the base or around the areoles. Nevertheless, very little is known about the nature of EFNs in cacti, and even there is doubt whether their exudate can be qualified as nectar. Preliminary study searching the location of NEFs in cacti showed drops of hyaline and sticky exudate covering the apex of spines inserted in the areola of young cladodes in Brasiliopuntia brasiliensis (Willd.) A. Berger. and Nopalea cochenillifera (L.) Salm-Dyckin. However, the use of a refractometer and glycophyte did not detect the presence of reducing sugars in the secretion. So, this work aims to characterize the morphology and functioning of the secretory spines in B. brasiliensis and N. cochenillifera and the chemical composition of the secretion. For this, glands in different developmental stages will be processed according to usual techniques for anatomical, histochemical and ultrastructural studies. Exudate samples will be analyzed by high performance anion exchange chromatography (HPAEC / PAD) to identify carbohydrates and by high performance liquid chromatography (HPLC) to identify sugars and amino acids. The results will be compared between the species seeking to identify the nature of the glands and the chemical composition of the secretion, in a functional context. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DE MELO SILVA, STEFANY CRISTINA; MACHADO, SILVIA RODRIGUES; NEPI, MASSIMO; RODRIGUES, TATIANE MARIA. Structure and function of secretory glochids and nectar composition in two Opuntioideae (Cactaceae) species. BOTANY, v. 98, n. 8, p. 425-437, AUG 2020. (17/14891-5)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

SILVA, Stefany Cristina de Melo. Anatomical, chemical and ultrastructural characterization of secretory spines in two species of Opuntioideae (Cactaceae).. 2019. Master's Dissertation - Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu Botucatu.