The Effects of Moderate and Severe Salinity on Composition and Physiology in the Biomass Crop Miscanthus × giganteus

Abstract

Saline land represents a growing resource that could be utilised for growing biomass crops, such as Miscanthus × giganteus (Greef et Deu.), for eliminating competition with staple food crops. However, the response mechanisms to different salinity regimes, in relation to the impact on quality of the harvested biomass and the combustion properties are largely unknown. Herein, the focus was on the salt-induced compositional changes of ion flux and compartmentalization in the rhizome, stems, and leaves in relation to their impact on salinity tolerance and the combustion quality through investigating the photophysiological, morphophysiological, and biochemical responses of M. × giganteus to moderate and a severe salinity. Severe salinity induced an immediate and sustained adverse response with a reduction in biomass yield, photoinhibition, and metabolic limitations in photosynthesis. Moderate salinity resulted in a slower cumulative response with low biomass losses. Biomass composition, variations in ion compartmentalisation and induction of proline were dependent on the severity and duration of salinity. Ash behaviour indices, including the base percentage and base-to-acid ratio, indicated lower corrosion potential and lower risk of slagging under salinity. Understanding the impact of salinity on the potential for growth on saline land may identify new targets for breeding salinity-tolerant bioenergy crops.

Physiological response of Miscanthus genotypes to salinity stress under elevated CO2

“…Consistent with this, in our study, the effect of salinity on A n could be due to the change in g s (Figure 2) indicating stomatal limitation played a major role in affecting photosynthesis. Consistent with our results, a previous study in M. sinensis showed that both g s and A n first increased and then dropped with the duration and increase in salt stress (Sun et al, 2021). Likewise, it was also suggested in Stevia rebaudiana plants, a parallel change in g s and A n indicated that restriction of photosynthesis under salinity could be due to stomatal limitation (Hussin et al, 2017).…”

“…Moreover, due to peculiar leaf anatomy and greater CO 2 assimilation mechanisms, compared with C 3 plants, C 4 plants are generally relatively less influenced by salinity (Roy & Mathur, 2021). For example, previous studies have reported that both Miscanthus sinensis and Miscanthus × giganteus exhibited high level of salt tolerance, although they withstand different severity of the stress (Hung et al, 2009; Stavridou et al, 2020).…”

Genetic Diversity and Synergistic Modulation of Salinity Tolerance Genes in Aegilops tauschii Coss

“…The mechanisms by which plants tolerate salinity stress are the following: (1) osmotic adjustment, (2) attenuation of salt concentration in the plant body through excretion (salt glands) and exclusion (from roots to leaves), and (3) preventing harmful effects on the plant body via compartmentalization [ 29 , 30 ]. A crop plant that maintains low Na + concentration and high dry weight biomass has more salinity tolerance than other populations [ 31 , 32 ]. The present study also reported salt excretion in Ae.…”

Proximate and mineral compositions of the green seaweeds Caulerpa lentilifera and Caulerpa racemosa from South Sulawesi Coast, Indonesia

“…The excessive ash content acquired shows an enormous diversity of mineral content [29]. The high ash content can be a result of the presence of salt inside the leaves [30] and the presence of varying amounts of minerals [28] due to the high salinity of seawater [31]. Seaweed has an excessive mineral content due to the fact it can absorb minerals from its environment.…”