Bioactive compounds and apoptotic effects of saffron (Crocus sativus L.) in different fertilizer conditions

Abstract

In this study, the qualitative traits of stigma (crocin, picrocrocin and safranal content) and the apoptotic effects of stamen and petal extracts (real-time PCR analysis for evaluating the expression of Bax, Bcl2, CAS3 and CAS6 genes) of saffron were investigated under organic and conventional conditions at the Agricultural Research Field of the University of Birjand, Iran over three years. The treatments included field age (one, two, and three-year-old farm) and also organic and conventional cultivations with different levels (low, moderate, and high levels) of cow manure and chemical fertilizers, respectively. The results indicated that the crocin, picrocrocin and safranal contents were considerably increased using organic and chemical fertilizers compared to the control. The highest crocin, picrocrocin and safranal contents were obtained under applying a high level of manure in organic farming system (OFS-H), that safranal content in this level have no significant difference with applying a moderate level of manure in organic farming system (OFS-M), and applying a high level of chemical fertilizers in conventional farming system (CFS-H). Among the field ages, the three-year-old farm resulted in the highest qualitative yield of saffron compared to the one-year-old farm and the two-year-old farm. The real-time PCR analysis also showed that petal and stamen extracts led to up-regulation of Bax, CAS3 and CAS6 (Pro-apoptotic genes) and down-regulation of Bcl2 (Anti-apoptotic gene) in both cultivation ways. The highest and the lowest bioactive compounds and the expression of Pro-apoptotic genes belonged to stamen extract at organic farming system and petal extract at conventional farming system, respectively. The findings of this study could significantly contribute to identification of the best crop management strategy for increasing the qualitative and medicinal properties of Saffron.