The effects of global warming and climate changes on plant growth in arid and semiarid regions have prompted the implementation of crop improvement strategies to mitigate these adverse impacts. One of these strategies involves the application of foliar treatments. A study including two irrigation levels with 70% and 50% field capacity, representing mild and severe drought stresses, respectively, and five spraying treatments were conducted. The spraying treatments included no spraying (control), zinc sulfate (ZnSO4: 3/1000), salicylic acid (SA: 40 mg/l), methyl jasmonate (MeJA: 2 mg/l), and auxin (IAA: 1/5 mg/l). It was observed that the levels of chlorophylls a and b in the leaves increased in response to drought stress. Furthermore, an escalation in the severity of drought stress resulted in heightened levels of secondary metabolites (crocin, picrocrocin, and safranal). Conversely, the dry weight of daughter corms decreased due to drought stress. Additionally, the proline, soluble sugars contents, and nitrogen, potassium, and zinc absorption were increased in MeJA and IAA-treated daughter corms under mild and severe drought stress conditions. On the other hand, phosphorous uptake decreased significantly under severe drought stress compared to mild stress conditions. Likewise, the application of MeJA and IAA significantly increased stigma and petal yields, as well as the content of secondary metabolites in saffron. Moreover, MeJA and IAA applications enhanced water use efficiency under both mild and severe drought stress conditions, highlighting their potential to reinforce the non-enzymatic defense system, increase daughter corm dry weight and nutrient uptake, improve saffron quality and quantity, and alleviate the adverse effects of drought stress in saffron plants however, further research is warranted to comprehensively understand these effects.

Herbal secondary metabolites possess high economic value, and the chemical synthesis of these metabolites is typically complex and costly. In light of this, the production of metabolites through various biotechnological methods, including plant cell and tissue culture, can offer a beneficial alternative. In this experiment, corm explants of saffron were collected from the Torbat-e Heydarieh, a native Iranian ecotype. After sterilization, they were cultured in ½ MS medium supplemented with different concentrations of NAA, IBA, and/or 2,4-D in combination with the BAP hormone at 21 °C under dark conditions. The experiment followed a completely randomized design with three repetitions for hormones and their levels. The findings revealed that, among the various callus induction media tested, the ½ MS medium, when supplemented with 0.5 mg/l of 2,4-D and 0.1 mg/l of BAP, demonstrated the highest percentage of callus formation. Meanwhile, the ½ MS medium with hormone combinations of 0.5 mg/l of BAP and 2 mg/l of IBA resulted in the lowest callusing. On the other hand, although NAA was effective for callus induction, the rooting percentage of calli is higher and is not suitable for callus induction or the establishment of suspension culture in saffron.Abbreviations: 2,4-D; 2,4-Dichlorophenoxyacetic acid, NAA; 1-Naphthaleneacetic acid, IBA; Indole-3-butyric acid, BAP; 6-Benzylaminopurine, MS; Murashige and Skoog medium

Herbal secondary metabolites possess high economic value, and the chemical synthesis of these metabolites is typically complex and costly. In light of this, the production of metabolites through various biotechnological methods, including plant cell and tissue culture, can offer a beneficial alternative. In this experiment, corm explants of saffron were collected from the Torbat-e Heydarieh, a native Iranian ecotype. After sterilization, they were cultured in ½ MS medium supplemented with different concentrations of NAA, IBA, and/or 2,4-D in combination with the BAP hormone at 21 °C under dark conditions. The experiment followed a completely randomized design with three repetitions for hormones and their levels. The findings revealed that, among the various callus induction media tested, the ½ MS medium, when supplemented with 0.5 mg/l of 2,4-D and 0.1 mg/l of BAP, demonstrated the highest percentage of callus formation. Meanwhile, the ½ MS medium with hormone combinations of 0.5 mg/l of BAP and 2 mg/l of IBA resulted in the lowest callusing. On the other hand, although NAA was effective for callus induction, the rooting percentage of calli is higher and is not suitable for callus induction or the establishment of suspension culture in saffron.Abbreviations: 2,4-D; 2,4-Dichlorophenoxyacetic acid, NAA; 1-Naphthaleneacetic acid, IBA; Indole-3-butyric acid, BAP; 6-Benzylaminopurine, MS; Murashige and Skoog medium

The natural lignan podophyllotoxin, a dimerized product of two phenylpropanoid moieties which occurs in a few plant species, is a pharmacologically important compound for its anticancer activities. Optimization of the in vitro cultures might lead to a renewable source of lignans for medicinal uses. In order to maximize efficiency of podophyllotoxin accumulation via in vitro cultures, the effect of different concentrations of a-Naphthalene acetic acid (NAA) (0, 0.4 and 1 mg/l), Kinetin (Kin) (0, 0.2 and 0.4 mg/l) and combinations of NAA and Kin [(0.4 and 0.2), (0.4 and 0.4), (1 and 0.2) and (1 and 0.4) mg/l] on growth and accumulation of podophyllotoxin in callus, cell culture and in vitro propagated plantlets of Linum album was evaluated. The highest growth and accumulation of podophyllotoxin in callus culture was obtained when it grown under dark condition in comparison to photoperiod.The biomass of cell and callus do not changed under various hormone concentrations. Content of podophyllotoxin was enhanced in cell and callus cultures supplemented with NAA 1 mg/l+Kin 0.4 mg/l. The experiments demonstrated Kin 0.2 or 0.4 mg/l stimulated multiplication and production of podophyllotoxin in shoot culture.