Hydropriming and Biopriming Improve Medicago truncatula Seed Germination and Upregulate DNA Repair and Antioxidant Genes

Abstract

Seed germination is a critical parameter for the successful development of sustainable agricultural practices. While seed germination is impaired by environmental constraints emerging from the climate change scenario, several types of simple procedures, known as priming, can be used to enhance it. Seed priming is defined as the process of regulating seed germination by managing a series of parameters during the initial stages of germination. Hydropriming is a highly accessible and economic technique that involves soaking of seeds in water followed by drying. Biopriming refers to the inoculation of seeds with beneficial microorganism. The present study aims to investigate whether hydropriming and biopriming could enhance seed germination. Thereby, the germination of Medicago truncatula seeds exposed to hydropriming and/or Bacillus spp. isolates was monitored for two-weeks. The seeds were sown in trays containing two types of in situ agricultural soils collected from Northern India (Karsara, Varanasi). This region is believed to be contaminated by solid waste from a nearby power plant. Phenotypic parameters had been monitored and compared to find the most appropriate combination of treatments. Additionally, qRT-PCR was used to evaluate the expression levels of specific genes used as molecular indicators of seed quality. The results show that, while hydropriming significantly enhanced seed germination percentage, biopriming resulted in improved seedling development, represented by increased biomass rather than seedling length. At a molecular level, this is reflected by the upregulation of genes involved in DNA damage repair and antioxidant defence. In conclusion, hydropriming and biopriming are efficient to improve seed germination and seedling establishment in soils collected from damaged sites of Northern India; this is reflected by morphological parameters and molecular hallmarks of seed quality.

Hydropriming Applied on Fast Germinating Solanum villosum Miller Seeds: Impact on Pre-germinative Metabolism

“…A progressive increase in oxidative DNA damage occurring during seed imbibition was measured in terms of 7,8-dihydro-8-oxoguanine (8-oxodG) levels, in the model legume Medicago truncatula ( Balestrazzi et al, 2011 ). The concomitant up-regulation of key BER (base excision repair) genes including OGG1 (8-oxoguanine glycosylase/lyase) and Tdp1a (tyrosyl-DNA phosphodiesterase) was also described ( Macovei et al, 2010 , 2011 ; Balestrazzi et al, 2011 ; Pagano et al, 2017 , 2019 ; Forti et al, 2020a , b ).…”

Biomagnetic Priming—Possible Strategy to Revitalize Old Mustard Seeds

“…Worldwide, different methods are being studied to improve seed germination, and biopriming as well as SMF treatment have been proposed as successful tools [Michalak et al, 2019; Forti et al, 2020]. In this study, we investigated the possibility of using B. amyloliquefaciens D5 ARV and SMF in priming of old white mustard seed.…”

“…Seed germination decrease during prolonged storage can be partially restored by seed priming treatments. Numerous priming methods are based on the use of chemical and physical agents [Zheng et al, 2016; Forti et al, 2020]. However, seed treatment with beneficial microorganisms represents a useful eco‐friendly alternative [Forti et al, 2020].…”

Priming Strategies for Benefiting Plant Performance under Toxic Trace Metal Exposure

“…During soaking, seeds bind water and absorb protective and biologically active compounds. As a result, the procedure activates various enzymes, metabolic pathways, and synthesis processes that are regarded as “pre-germinative metabolism” [ 43 , 44 ]. Promoting effects are then manifested in developing seedlings and sustain their higher vigor and survivability under unfavorable environmental conditions.…”

“…Genetic control of the priming phenomenon involves the regulation of numerous pathways activated during pre-treatment and subsequent stress events. New information on its mechanisms are gathered due to “omics” analyses that decipher changes in the transcriptome, proteome, and metabolome of primed plants [ 44 , 140 , 141 , 142 ]. However, the details of genetic control during priming against metallic stress are not fully elucidated.…”