Ion absorption and allocation of carbon resources in excised pea roots grown in liquid medium in absence or presence of NaC1
1987
Solomon, M. | Ariel, R. | Hodson, M.J. | Mayer, A.M. | Poljakoff-Mayber, A.
Freshly excised pea roots (Pisum sativum cv. Alaska) when transferred to growth medium (130 mOsm) or growth medium containing salt ( ∼ 370 mOsm) suffer an initial osmotic shock and lose water. Contol roots tended to accumulate potassium, particularly in the apical zone, while those exposed to NaCl accumulated mainly sodium, potassium accumulation being depressed. Exposure to salinity for 6 d caused increases in root protein, cellulose, uronic acid and lignin content per cell. In roots supplied with 14C-glucose for 24 h immediately after excision there was little difference in uptake of glucose and in its use in respiration between control and salt treated roots. However, there were noticeable differences in incorporation of labelled carbon into several cell fractions, and particularly into the cellulose fraction in the upper parts of the root. When roots were grown for six days in culture before being supplied with [14C]glucose, uptake per root was greater in the 120 mM NaCl treatment, and the fraction diverted to respiration was decreased by salinity. On a per cell basis incorporation into soluble starch, uronic acid and cellulose fractions was increased in the salt treated roots. The data obtained are in accord with the previous findings and are suggestive of increased synthesis of cell wall materials. No conclusion could be drawn as to whether the changes described are of adaptive value.
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