Intercellular pectic protuberances in Hymenaea stigonocarpa (Fabaceae, Caesalpinioideae): occurrence and functional...

Area of Science:

• Plant anatomy
• Plant physiology
• Ultrastructural biology

Background:

• Hymenaea stigonocarpa is a tropical tree species.
• Floral nectaries and leaf mesophyll are crucial for plant survival and reproduction.
• Understanding plant cell structures can reveal mechanisms of transport and support.

Purpose of the Study:

• To investigate the anatomical and ultrastructural features of Hymenaea stigonocarpa leaf mesophyll and floral nectaries.
• To identify and characterize intercellular pectic protuberances (IPPs) in these tissues.
• To elucidate the formation and potential function of IPPs.

Main Methods:

• Light microscopy
• Transmission electron microscopy
• Scanning electron microscopy
• Standard fixation and processing techniques for plant tissues

Main Results:

• Intercellular pectic protuberances (IPPs) were identified linking adjacent cells in both leaf palisade mesophyll and floral nectary secretory parenchyma.
• IPPs appeared as scalae in palisade cells and strands in secretory parenchyma.
• Evidence suggests IPPs form from cell separation during expansion and intercellular space development, rather than specific synthesis.
• IPPs were observed to increase cellular contact.

Conclusions:

• Intercellular pectic protuberances (IPPs) are present in Hymenaea stigonocarpa leaf and floral nectary tissues.
• IPPs are likely formed passively through cell expansion and the development of intercellular spaces.
• These structures may play a role in enhancing cellular contact and facilitating apoplastic transport in plants.