Here we report the effects of SNP, a nitric oxide donor on sucrose metabolizing enzymes, acid and alkaline invertase (EC 3.2.1.26 and 3.2.1.153) and ubiquitous alkaline phosphatase (EC 3.1.3.1) in four lemongrass varieties viz., Krishna, Cauveri, Nima and Cheerharit. For the study, two 15 d lemongrass tillers were cut and immediately dipped into the test tubes containing SNP solution (5 mL) of variable strength (1 to 5 mM) and one without SNP (as control); kept for 4 h under mild sunlight. The results revealed that moderate SNP concentration (2 mM) was most effective, caused drastic reduction (40%) in protein content in var. Nima followed by Krishna (33%), Cauveri (17%) and Cheerharit (12%). In contrast, SNP (1 mM) has impressively enhanced protein content in all the lemongrass varieties. The SNP (2 mM) markedly inhibited the activity of acid invertase by 38% in Cheerharit, 35% Nima and 28% Cauveri whereas and alkaline invertase by 21, 28 and 24% respectively in var. Cheerharit, Nima and Krishna. Similarly, SNP (5 mM) severely inhibited (~ 63%) the activity of the ALP in lemongrass var. Cauveri and Nima, 50% in Krishna and relatively less 23% in Cheerharit as compared to the control. However, in var. Nima, 50% loss in ALP activity had already been occurred after 2 mM SNP treatment. These results primarily suggests that NO interferes sucrose metabolism by anonymously hindering the activity of acid and alkaline invertase and ubiquitous alkaline phosphatase in lemongrasses
