Salinity Effects on Germination and Mobilization of Reserves in Jojoba Seed

Abstract

Jojoba [Simmondsia chinensis (Link) C.K. Schneid.] is a new oil (wax) seed crop for arid and semiarid environments where salinity is frequently a major problem. The objectives of this work were to study the effects of salinity on germination and mobilization of reserves in jojoba seed. Salt concentrations (NaCl:CaCl2 1:1, w/w) having electrical conductivities (EC) of 0, 5, 10, and 15 dS/m significantly reduced germination, fresh weight of seedlings, and the amount of lipid used in ‘Vista’ jojoba. Germination was reduced from 82.6% in nonsaline conditions to 42.6%, fresh weight was reduced from 314 to 98 mg, and the amount of lipid used was reduced from 136 to 83 mg in strong (EC = 15.0 dS/m) saline treatments. Higher levels of salinity also resulted in accumulation of total soluble sugars, delayed initiation of germination and lipid breakdown, and decreased C38 and C40 esters with an increase in C42. These data suggest jojoba is not salt‐tolerant during germination.

Source–sink regulation of cotyledonary reserve mobilization during cashew (Anacardium occidentale) seedling establishment under NaCl salinity

“…In this study, storage protein hydrolysis was delayed by NaCl salinity since seed germination, whereas in cowpea it occurred at late seedling establishment (Prisco and Vieira, 1976) and it was not affected through seedling growth in maize (Ashraf and Wahid, 2000) and sunflower (Ashraf et al, 2003). In addition, lipid breakdown was retarded by salt stress during seed germination in jojoba (Kayani et al, 1990), maize (Ashraf and Wahid, 2000) and sunflower (Ashraf et al, 2003), but it was impaired only at late seedling growth in cashew (Figure 2b). Thus, it is suggested that reserve mobilization is markedly delayed at distinct critical stages of seedling establishment in different species, as salinity decreased the growing axis requirements for specific products of hydrolysis.…”

“…Lipid breakdown during early cashew development was previously reported (Cavalcanti Jùnior, 1994), but its possible role in transient starch synthesis was not investigated. As in cashew, lipid breakdown was also coordinated with transient starch accumulation in jojoba seedlings, yielding soluble sugars for carbon transport to the growing axis at later stages (Kayani et al, 1990).…”

“…In jojoba (Simmondsia chinensis) seedlings under high salinity, lipid breakdown was retarded as soluble sugars were accumulated in the cotyledons (Kayani et al, 1990). Moreover, the salt-induced delay of lipid breakdown in two Medicago species was attributed to decreased activity of the glyoxysomal enzymes catalase, isocitrate lyase and malate synthetase, which play a role in carbohydrate synthesis from fatty acid moieties during seedling establishment (Miled-Dauod and Cherif, 1991).…”

Physiology of cashew plants grown under adverse conditions

“…Salinity affects seed germination by inhibiting water absorption and cellular extension (Kayani et al, 1990;Franco et al, 1993;Katembe et al, 1998;Torres et al, 2000;Al-Karaki, 2001;Almansouri et al, 2001). This may be due to the reduction in water absorption during the imbibition phase or the excessive absorption of toxic ions, especially Na + and Cl - (Prisco and O'Leary, 1970), which alter metabolism by inhibiting or delaying mobilization of storage reserves and damaging the membrane system of the embryonic axis (Prisco et al, 1981;Gomes-Filho and Prisco, 1983;Chartzoulakis and Klapaki, 2000;Murillo-Amador et al, 2002).…”

Mutants of Arabidopsis thaliana Capable of Germination under Saline Conditions

“…The disassociation between tolerance at germination and tolerance during growth and subsequent development was anticipated. Radicle emergence coincides with the inception of pronounced salt sensitivity in most crop plants, and the seedling stage of development is often the most salt sensitive in both glycophytic and halophytic plants (West and Taylor, 1981;Kayani et al, 1990).…”