A robust workflow for indirect somatic embryogenesis and cormlet production in saffron (Crocus sativus L.) and its wild allies; C. caspius and C. speciosus

Abstract

Saffron (Crocus sativus L.) and its wild relatives, Crocus caspius and Crocus speciosus are of considerable significance in the pharmaceutical, nutraceutical, and ornamental bulbs industry. Towards the ultimate goal of the conservation of wild Crocus species and establishment of an efficient workflow for in vitro production of Crocuses, efficient protocols were developed for disinfection and in vitro production of cormlets in C. sativus and its wild allies C. caspius and C. speciosus. Moreover, the differential expression of the Somatic Embryogenesis Receptor-like Kinase (SERK) gene was evaluated as a potential molecular marker during embryogenesis between embryogenic and non-embryogenic calli. A highly efficient disinfection recipe and a low-cost TDZ-free protocol have been successfully developed for in vitro cormlet production in three Crocus species. MS medium containing 10.18 μM 2, 4-D þ 4.44 μM BAP was most efficiently induced callus and somatic embryo formation. The highest conversion frequency and maximum cormlet weight were achieved in MS containing 5.37 μM NAA þ 8.88 μM BAP. The SERK expression was significantly much higher in embryogenic calli than non-embryogenic in all Crocus species. The current low-cost and easy-to-use recipe suggests a promising in vitro propagation workflow for mass production of uniform pathogen-free cormlets of Crocus species, as well as a platform to better conservation of wild Crocus species and effective gene and genome editing using CRISPR-Cas9 in future studies.

A Review on Flower Bulb Micropropagation: Challenges and Opportunities

“…Kumar et al [142] used the bulb scales of the critically endangered Fritillaria roylei for in vitro culture. Sevindik and Mendi [143], Taheri-Dehkordi et al [144] used the corms as explants to propagate the C. sativus L. Furthermore, Slimani et al [145] informed us that the vegetative apices, apical and axillary buds, meristematic zone, segments, leaves, ovaries, protoplasts, corms, and roots are useful to induce the somatic embryogenesis of C. sativus L.…”

Saffron In Vitro Propagation: An Innovative Method by Temporary Immersion System (TIS), Integrated with Machine Learning Analysis

“…Many papers that have reported on in vitro saffron propagation come from several countries [5,7,[38][39][40][41] and some reviews [42][43][44] have collected all the information on this fundamental method for propagating the Crocus spp. [2], especially in C. sativus, to develop callus or new shoot buds and obtain new microcorms formation.…”

“…Therefore, different propagation pathways, such as in vitro culture, have been investigated. In vitro propagation has already been successfully applied to saffron from different geographical origins, i.e., Iran [5], India [6], Morocco [7], Türkiye [8], China [9], and Spain [10], allowing its culture in sterile, controlled conditions and without season dependency. However, the Temporary Immersion System (TIS) approach can be considered for large-scale in vitro propagation and rapid acclimatization.…”

Computational screening of miRNAs and their targets in saffron (Crocus sativus L.) by transcriptome mining

“…This species spreads from central Europe to western China (Harpke et al 2013). Iran is known as the world's largest producer of saffron, and in recent years, more attention has been dedicated to this valuable plant due to its advantages over other crops, such as higher price and low water needs (Vahedi et al 2018;Taheri-Dehkordi et al 2020). The color, flavor, and aroma of saffron are attributed to particular apocarotenoids named crocin, picrocrocin, and safranal (Tarantilis et al 1995).…”

“…The color, flavor, and aroma of saffron are attributed to particular apocarotenoids named crocin, picrocrocin, and safranal (Tarantilis et al 1995). Increasing demand for saffron's active ingredients, on the one hand, and its sterile nature (2n = 3x = 24), which renders traditional breeding methods ineffective for increasing the amounts of its active ingredients, on the other, have prompted researchers to turn their attention to the use of molecular breeding methods (Taheri-Dehkordi et al 2020). Metabolic engineering is an approach for increasing apocarotenoids in saffron.…”