A structural review of foliar glands in Passiflora L. (Passifloraceae).

Extrafloral glands in Passifloraceae species have aroused the interest of many researchers because of their wide morphological diversity. The present work analyzed the foliar glands on 34 species of Passiflora from samples containing glands in the petiole and foliar blade fixed in 50% solution of fo...

Full description

Bibliographic Details
Main Authors: Renata Cristina Cassimiro de Lemos, Delmira da Costa Silva, Gladys Flavia de Albuquerque Melo-de-Pinna
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2017-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC5685584?pdf=render
_version_ 1811282535735361536
author Renata Cristina Cassimiro de Lemos
Delmira da Costa Silva
Gladys Flavia de Albuquerque Melo-de-Pinna
author_facet Renata Cristina Cassimiro de Lemos
Delmira da Costa Silva
Gladys Flavia de Albuquerque Melo-de-Pinna
author_sort Renata Cristina Cassimiro de Lemos
collection DOAJ
description Extrafloral glands in Passifloraceae species have aroused the interest of many researchers because of their wide morphological diversity. The present work analyzed the foliar glands on 34 species of Passiflora from samples containing glands in the petiole and foliar blade fixed in 50% solution of formaldehyde-ethanol-acetic acid and stored in a 70% ethanol solution. For anatomical analyses, part of the material was embedded in Paraplast, longitudinally sectioned and double stained with safranin and astra blue. Scanning electron microscopy analysis was also carried out. To analyze the presence of sugars in the secretion of foliar glands, a glucose strip test was used. Based on the results of morphological, anatomical and glucose strip tests, the foliar secretory glands in Passiflora can be grouped into two categories: Type I glands, defined as nectaries, can be elevated or flattened, and can have a sugar content high enough to be detected by the glucose strip test analysis. Type II glands are elevated and did not show a positive reaction to the glucose strip test. From an anatomical viewpoint, glands characterized as extrafloral nectaries show a multistratified secretory epidermis, typically followed by two flat layers of nectariferous parenchyma with dense content. Internal to these layers, vascular bundles are immersed in the subsecretory parenchyma and terminate in phloem cells. On the other hand, type II glands show a single layer of elongated secretory epidermal cells. Internal to this single layer, parenchyma and vascular tissue with both phloem and xylem elements can be observed. The analyzed species show a wide diversity of gland shape and distribution, and the combined analysis of morphology, anatomy and preliminary tests for the presence of glucose in the exudate in different Passiflora subgenera suggests the occurrence of two categories of glands: nectaries and resin glands.
first_indexed 2024-04-13T01:54:26Z
format Article
id doaj.art-d458eaa7d74d42d2853762ef5b2d4989
institution Directory Open Access Journal
issn 1932-6203
language English
last_indexed 2024-04-13T01:54:26Z
publishDate 2017-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj.art-d458eaa7d74d42d2853762ef5b2d49892022-12-22T03:07:48ZengPublic Library of Science (PLoS)PLoS ONE1932-62032017-01-011211e018790510.1371/journal.pone.0187905A structural review of foliar glands in Passiflora L. (Passifloraceae).Renata Cristina Cassimiro de LemosDelmira da Costa SilvaGladys Flavia de Albuquerque Melo-de-PinnaExtrafloral glands in Passifloraceae species have aroused the interest of many researchers because of their wide morphological diversity. The present work analyzed the foliar glands on 34 species of Passiflora from samples containing glands in the petiole and foliar blade fixed in 50% solution of formaldehyde-ethanol-acetic acid and stored in a 70% ethanol solution. For anatomical analyses, part of the material was embedded in Paraplast, longitudinally sectioned and double stained with safranin and astra blue. Scanning electron microscopy analysis was also carried out. To analyze the presence of sugars in the secretion of foliar glands, a glucose strip test was used. Based on the results of morphological, anatomical and glucose strip tests, the foliar secretory glands in Passiflora can be grouped into two categories: Type I glands, defined as nectaries, can be elevated or flattened, and can have a sugar content high enough to be detected by the glucose strip test analysis. Type II glands are elevated and did not show a positive reaction to the glucose strip test. From an anatomical viewpoint, glands characterized as extrafloral nectaries show a multistratified secretory epidermis, typically followed by two flat layers of nectariferous parenchyma with dense content. Internal to these layers, vascular bundles are immersed in the subsecretory parenchyma and terminate in phloem cells. On the other hand, type II glands show a single layer of elongated secretory epidermal cells. Internal to this single layer, parenchyma and vascular tissue with both phloem and xylem elements can be observed. The analyzed species show a wide diversity of gland shape and distribution, and the combined analysis of morphology, anatomy and preliminary tests for the presence of glucose in the exudate in different Passiflora subgenera suggests the occurrence of two categories of glands: nectaries and resin glands.http://europepmc.org/articles/PMC5685584?pdf=render
spellingShingle Renata Cristina Cassimiro de Lemos
Delmira da Costa Silva
Gladys Flavia de Albuquerque Melo-de-Pinna
A structural review of foliar glands in Passiflora L. (Passifloraceae).
PLoS ONE
title A structural review of foliar glands in Passiflora L. (Passifloraceae).
title_full A structural review of foliar glands in Passiflora L. (Passifloraceae).
title_fullStr A structural review of foliar glands in Passiflora L. (Passifloraceae).
title_full_unstemmed A structural review of foliar glands in Passiflora L. (Passifloraceae).
title_short A structural review of foliar glands in Passiflora L. (Passifloraceae).
title_sort structural review of foliar glands in passiflora l passifloraceae
url http://europepmc.org/articles/PMC5685584?pdf=render
work_keys_str_mv AT renatacristinacassimirodelemos astructuralreviewoffoliarglandsinpassifloralpassifloraceae
AT delmiradacostasilva astructuralreviewoffoliarglandsinpassifloralpassifloraceae
AT gladysflaviadealbuquerquemelodepinna astructuralreviewoffoliarglandsinpassifloralpassifloraceae
AT renatacristinacassimirodelemos structuralreviewoffoliarglandsinpassifloralpassifloraceae
AT delmiradacostasilva structuralreviewoffoliarglandsinpassifloralpassifloraceae
AT gladysflaviadealbuquerquemelodepinna structuralreviewoffoliarglandsinpassifloralpassifloraceae