S-methylmethionine reduces cell membrane damage in higher plants exposed to low-temperature stress.
S-methylmethionine (SMM), an important intermediate compound in the sulphur metabolism, can be found in various quantities in majority of plants. The experiments were designed to determine the extent to which SMM is able to preserve cell membrane integrity or reduce the degree of membrane damage in the course of low-temperature stress. By measuring electrolyte leakage (EL), it was proved that SMM treatment reduced cell membrane damage, and thus EL, during low-temperature stress in both the leaves and roots of peas, maize, soy beans and eight winter wheat varieties with different levels of frost resistance. Investigations on the interaction between SMM and polyamine biosynthesis revealed that SMM increased the quantities of agmatine (Agm) and putrescine (Put) as well as that of spermidine (Spd), while it had no effect on the quantity of spermine (Spn). Using a specific inhibitor, methylglyoxal-bis-guanyl hydrazone (MGBG), it was proved that the polyamine metabolic pathway starting from methionine played no role in the synthesis of Spd or Spn, so there must be an alternative pathway for the synthesis of SMM-induced polyamines.
Rácz
Ilona
I
Department of Plant Physiology, Eötvös Loránd University, Budapest, Hungary. raczil@ludens.elte.hu
Páldi
Emil
E
Szalai
Gabriella
G
Janda
Tibor
T
Pál
Magdolna
M
Lásztity
Demeter
D
D002462:Cell Membrane / Q000187:drug effects*; D003080:Cold Temperature; D004573:Electrolytes; D008935:Mitoguazone / Q000494:pharmacology; D018532:Pisum sativum / Q000187:drug effects / Q000378:metabolism; D059828:Plant Cells; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D010944:Plants / Q000187:drug effects* / Q000378:metabolism; D011073:Polyamines / Q000378:metabolism; D013312:Stress, Physiological / Q000187:drug effects*; D014908:Triticum / Q000187:drug effects / Q000378:metabolism; D014814:Vitamin U / Q000494:pharmacology*; D003313:Zea mays / Q000187:drug effects / Q000378:metabolism
D004573:Electrolytes; D011073:Polyamines; D014814:Vitamin U; D008935:Mitoguazone