Potential involvement of rapeseed (Brassica napus L.) metallothioneins in the hydrogen peroxide‐induced regulation of seed vigour

Abstract

Germination is a crucial process in crop plant life cycle that determines future yield. Hydrogen peroxide plays a significant role in both dormancy release and seed ageing. The potential of the rapeseed metallothioneins (BnMT1‐4) as reactive oxygen species scavengers was investigated. In the presence of H2O2, bacterial cells expressing BnMT1‐4 had higher growth rate than control cells. However, such effect was not observed in an oxidative stress oversensitive yap‐1Δ yeast mutant strain expressing BnMT1‐4. Next, it was shown that H2O2, up to 100 and 10 mM, promotes rapeseed germination rate and seedling growth, respectively. Moreover, it was demonstrated that in seeds germinating in the presence of H2O2, the expression of seed‐specific BnMT4 decreases to a high extent in a dose‐ and time‐dependent manner. It was shown that the decline in BnMT4 mRNA level, accelerated by up to 10 mM H2O2 treatment, correlates positively with increased rapeseed germination and early growth, underscoring the plausible role of BnMT4 as a H2O2 scavenging protein that level has to be downregulated in conditions where the compound is needed. Finally, it was demonstrated that H2O2 could be used as a priming agent of rapeseeds.

The Impact of Forest Fungi on Promoting Growth and Development of Brassica napus L.

“…The expression of MTs genes is also changed in plants inoculated with bacteria that promote their growth, which is confirmed by the research of Hrynkiewicz et al [48]. In contrast, in oil palm (Elaeis guineensis), the expression of type-3 MT increased in roots and leaves as a result of inoculation with the pathogenic fungus Ganoderma bininense and the symbiotic fungus Trichoderma harzianum [30]. Research by Voiblet et al [57] showed that MT expression was downregulated in Eucalypus globus in the presence of the fungus Pisolithus tinctorius.…”

“…One example is the induction of expression by MT1, MT2, and MT3 in B. rapa [68]. Research by Mierek-Adamska et al [30] showed that BnMT1-BnMT4 in rapeseed perform an antioxidant function when they are over-expressed in bacteria. Under stress conditions, plants activate additional processes to allow survival, with genes encoding oxidative enzymes and MTs being expressed [69].…”

“…Sterile seeds (20-30 items) were placed in 150 mm diameter Petri dishes containing MS medium without growth regulators (MS0, Murashige and Skoog [30]) and placed in a culture chamber (continuous light, temperature 25 ± 1 • C). Three to four days after sowing, four rapeseed seedlings with similar root length (1-2 cm) were transferred into sterile dishes containing MS0 medium.…”

“…Cis-elements responsible for the response to the presence of fungal elicitors are present in the MT genes promoters [27]. In higher plants, individual types of metallothioneins show organ-and tissue-specific expression, but expression can differ greatly between species [28][29][30]. In Brassica napus, there are four types of MT (BnMT1-BnMT4), of which type 4 (BnMT4) is expressed only in seeds and early stages of seedling growth [30,31].…”

In Silico Study of the RSH (RelA/SpoT Homologs) Gene Family and Expression Analysis in Response to PGPR Bacteria and Salinity in Brassica napus

“…Prior cDNA synthesis from 1 µg of RNA genomic DNA was removed using RNAse free DNase I (Thermo Fisher Scientific, Waltham, MA, USA). Further oligo(dT) 18 primer and RevertAid reverse transcriptase (Thermo Fisher Scientific, Waltham, MA, USA) were used for cDNA synthesis, in accordance with the protocol described in [84].…”