The Sweet Taste of Adapting to the Desert: Fructan Metabolism in Agave Species.

Arely V Pérez-López,June Simpson

doi:10.3389/fpls.2020.00324

Abstract

Over 70% of Agave species, (159 of 206) are found in Mexico and are well adapted to survive under hot, arid conditions, often in marginal terrain, due to a unique combination of morphological and physiological attributes. In the pre-Columbian era agaves were also key to human adaptation to desert terrain. In contrast to other species such as cacti or resurrection plants, Agaves store carbohydrates in the form of fructan polymers rather than starch or sucrose, however, properties specific to fructans such as a strong hydration shell, the ability to be transported through phloem, variable composition throughout the Agave life-cycle and accumulation in succulent tissues and flowers suggest a potential for multiple functional roles. This mini-review summarizes current knowledge of molecular and biochemical aspects of fructan metabolism in Agave species.

Highlights

Fructan polymers, are synthesized by some bacteria and fungi and an estimated 15% of angiosperms including both monocotyledons and dicotyledons from different genera (Hendry, 1993; Figure 1)
Neo type fructans have only been described in monocotyledons, no strong correlation exists between the type of fructan polymers and the genus or species in which they occur, supporting independent evolution of fructan metabolism
The presence of oligofructans containing 3–5 fructan residues (3–5 degrees of polymerization, D.P.) in Agave leaves indicates that sucrose produced by photosynthesis is metabolized to produce fructans rather than starch (Wang and Nobel, 1998) have shown that these oligofructans can accumulate in vascular tissue and are transported through the phloem

Summary

Introduction

Fructan polymers, are synthesized by some bacteria and fungi and an estimated 15% of angiosperms including both monocotyledons and dicotyledons from different genera (Hendry, 1993; Figure 1). The presence of oligofructans containing 3–5 fructan residues (3–5 degrees of polymerization, D.P.) in Agave leaves indicates that sucrose produced by photosynthesis is metabolized to produce fructans rather than starch (Wang and Nobel, 1998) have shown that these oligofructans can accumulate in vascular tissue and are transported through the phloem.

Results

Conclusion