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.

Medicinal plants are among valuable natural resources and sources of potentially curative safe drugs. They have been playing important roles in alleviating human sufferings by contributing herbal medicines in the primary to health care systems of rural and remote hilly areas where the health of society depends on folklore and traditional systems of medication. On the other hand, most crop seeds have within themselves the physiological phenomenon of dormancy afterb being harvested. Bunium persicum (Boiss.) B. Fedtsch, (or Carum persicum) is a grassy plant belonging to umbelliferae (Apiaceae) family with dormant seeds. It grows wildly on the mountainous areas of Iran. Several therapeutic properties including those reloted to digestive disorders, urinary tract disorders, diuretic gynaecologic, anti-convulsion, anti-helmetic as well as anti-asthma, and dyspnea, have been recognized and mentioned for the seeds of this plant as evident from ancient Iranian medical books. Because of these pharmaceutical effects, termination of seed dormancy before cultivation is necessary and important. Studies about the phenology of Bunium persicum show that the seeds germinat in spring and require exposure to cold temperature prior to germination. Also previous studies have shown that some concentration of plant growth regulators help the overcoming having seed dormancy in this plant. In this research, treatments were consisted of dry storage (the seeds having been collected in 2001 and in 2004), cold stratification (0, 2, 4, 6, 8, 10 weeks) at 4oC in refrigerator and treatment with plant growth regulators (GA3, KI, GA3+KI and H20). Simple and combined effects of treatments on seed germination were investigated and recorded following 3 weeks of being placed in a germinator. The treatments were arranged as a three level factorial. The data were analyzed and statistically compared using on the basis of a Randomized Block Design of three replications. The results revealed that 10 weeks of cold stratification along with 3 years of dry storage could enhance seed germination to an acceptable level.

Chlorella has applications in medicine, industry and food. For this reason, increase of biomass and its metabolites is valuable. Aim of this study was to obtain the best substance or phytohormone combinations to increase biomass and metabolites contents of Chlorella sorokiniana. In this study, Chlorella sorokiniana was cultured in modified Bold Basal Medium (BBM). Different proportions of plant hormones, naphthalene acetic acid (NAA), indolebutyric acid (IBA) and kinetin (Kin), nitrate and phosphate and thiamine pyrophosphate were added to medium. There was significant rise in dry weight, photosynthetic pigments and protein contents in treatment NAA (10mg. L-1) + Kin (1mg. L-1) compared with control. In treatment of IBA+ Kin, and thiamine pyrophosphate no significant difference was observed in these parameters. The highest significant enhancement of dry weight, metabolites and protein contents were observed in medium supplemented with higher amount of nitrate and phosphate.