Salt-stress-induced proline accumulation in germinating embryos:Evidence suggesting a role of proline in seed germination

The variability in proline content was studied with an objective to find out its physiological role in embryo germination in response to salt stress and phytohormone abscisic acid (ABA). In comparison with control, germination decreased markedly under NaCl and ABA treatments. The percentage decrease of germination under NaCl (35%) was more than ABA (65%). Subsequently, a significant increase in proline content was observed after both treatments. The relative increase in proline content was more under salt stress (703%) than ABA (301%). There was strong negative correlation (R2=-0.88) between germination capacity and increase in proline content. Based upon these results, a possible physiological role of proline in sorghum embryos is discussed.