Silver nanoparticles induce genetic, biochemical, and phenotype variation in chrysanthemum

Alicja Tymoszuk,Dariusz Kulus

doi:10.1007/s11240-020-01920-4

Abstract

Despite the tremendous progress in breeding, novel and user-friendly techniques of plant improvement are desirable. The study aimed to analyze the usefulness of silver nanoparticles (AgNPs) in the breeding of chrysanthemum: one of the top ornamental plant species. In vitro regeneration of adventitious shoots from internodes of chrysanthemum ‘Lilac Wonder’ was induced on the modified Murashige and Skoog (MS) medium supplemented with 0.6 mg L−1 6-benzylaminopurine (BAP), 2 mg L−1 indole-3-acetic acid (IAA) and AgNPs at 0, 5, 10 and 20 ppm concentration. The efficiency of callogenesis and caulogenesis were analyzed after 10 weeks of culture. The concentration of chlorophylls, carotenoids, and phenolic compounds in shoots and calli were estimated. Plants obtained from 20 ppm AgNPs treatment were additionally analyzed on the genetic level using randomly amplified polymorphic DNA (RAPD) and inter simple sequence repeats (ISSR) markers. In vitro rooted shoots were acclimatized in the glasshouse and subjected to biochemical and phenotype stability evaluation. AgNPs at the highest concentration (20 ppm) suppressed both callogenesis and caulogenesis in vitro. The concentration of metabolites in callus was stable, regardless of AgNPs treatment, except for carotenoids which production was enhanced by 20 ppm AgNPs. In contrast, the content of chlorophyll a and b in shoots varied depending on AgNPs treatment. Polymorphic loci were detected in 12 and 9 AgNPs-treated-plants by RAPD and ISSR markers, respectively (one of which was common to both marker systems). Rooting and acclimatization were fully successful in all experimental combinations. Phenotype alternations were detected in six plants; one from 10 ppm AgNPs treatment and five from 20 ppm treatment. They included variation in pigment content (anthocyanins and carotenoids) and/or inflorescence shape. Interestingly, only two plants revealed both genetic and phenotype polymorphisms. No genetic or phenotype variation was detected in the control plants. In conclusion, AgNPs can be used in chrysanthemum breeding.

Highlights

Chrysanthemum × grandiflorum /Ramat./Kitam. is one of the most valuable and popular ornamental plant species in the horticultural market
The first adventitious shoots appeared in the third week of culture on control explants and explants cultured on media with AgNPs (Fig. 2)
The highest increase in the number of shoots produced on internodes cultured on media with the addition of AgNPs was recorded between the third and fifth week, regardless of nanoparticle concentration

Summary

Introduction

Chrysanthemum × grandiflorum /Ramat./Kitam. is one of the most valuable and popular ornamental plant species in the horticultural market. Is one of the most valuable and popular ornamental plant species in the horticultural market. It is produced for cut flowers, in pots, undercover and in the ground. Chrysanthemum occupies the second place on the world sales list, following the rose (Miler and Jędrzejczyk 2018). This popularity is due to various-shaped and multi-colored inflorescences, long flowering period, habit diversity, as well as broad use in horticulture and medicine (Mukherjee et al 2013). To other plant species, mutations in chrysanthemum are usually recessive, i.e. the dominant allele changes to the recessive type, which makes the effect identified on the phenotype level when in homozygous combination (Nanjundiah 1993). The addition of metal nano-colloids into the culture medium can become a cheap, easy, and effective way to stimulate the explant regeneration (Tymoszuk and Miler 2019), and to induce genetic variation

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Discussion

Conclusion