Somatostatin-like material is present in flowering plants

Area of Science:

• Biochemistry
• Evolutionary Biology
• Plant Science

Background:

• Somatostatin (SRIF) is a vertebrate peptide hormone.
• SRIF-related material has been previously identified in bacteria.

Purpose of the Study:

• To investigate the presence and characteristics of SRIF-related material in higher plants.
• To explore the evolutionary origins of vertebrate-type peptide hormones.

Main Methods:

• High-performance liquid chromatography (HPLC) for purification.
• N- and C-terminal specific immunoassays for characterization.
• Bioassays to determine biological activity.
• Analysis of spinach and Lemna gibba G3 extracts.

Main Results:

• Spinach extracts contained SRIF-related material (6-80 pg/g wet wt) with two major molecular weight forms, similar to SRIF-28 and SRIF-14.
• Lemna gibba G3 extracts also showed SRIF-related material (3.0 pg/g wet wt).
• The purified plant material exhibited bioactivity, neutralized by anti-SRIF antiserum.

Conclusions:

• Higher plants possess somatostatin-like material.
• The presence of SRIF-like peptides in plants supports an ancient evolutionary origin for vertebrate-type peptide hormones.
• This finding suggests a conserved biological function across different kingdoms.