Accumulation of trehalose and sucrose in cyanobacteria exposed to matric water stress.

The drought-resistant cyanobacteria Phormidium autumnale, strain LPP(4), and a Chroococcidiopsis sp. accumulated trehalose, sucrose, and both trehalose and sucrose, respectively, in response to matric water stress. Accumulated sugar concentrations reached values of up to 6.2 mug of trehalose per mug of chlorophyll in P. autumnale, 6.9 mug of sucrose per mug of chlorophyll in LPP(4), and 4.1 mug of sucrose and 3.2 mug of trehalose per mug of chlorophyll in the Chroococcidiopsis sp. The same sugars were accumulated by these cyanobacteria in similar concentrations under osmotic water stress. Cyanobacteria that did not show drought resistance (Plectonema boryanum and Synechococcus strain PCC 7942) did not accumulate significant amounts of sugars when matric water stress was applied.