Drought-tolerance mechanisms in foxtail millet (Setaria italica) and proso millet (Panicum miliaceum) under different nitrogen supply and sowing dates

Abstract

Drought stress is one of the main limitations to crop growth and yield. Efficient nitrogen (N) nutrition may moderate the negative effects of drought stress on plants through retention of metabolic activities. The present study was conducted to investigate the biochemical responses of two millet species, foxtail millet (Setaria italica (L.) P.Beauv.) and proso millet (Panicum miliaceum L.), under two irrigation regimes (based on 55% and 85% soil-water depletion) and two N fertiliser levels (0 and 112.5 kg N ha–1) at four sowing dates (22 June and 6 July 2015, 14 and 30 June 2016). Drought stress increased hydrogen peroxide (H2O2), malondialdehyde (MDA) and other aldehyde contents of the plants, ultimately leading to 52% and 55% reductions in grain yield in foxtail millet and proso millet, respectively. Antioxidant activities showed significant increases under drought stress. Nitrogen application decreased H2O2, MDA and other aldehyde contents and activities of antioxidant enzymes, whereas it increased chlorophyll, carotenoid, phenolic compound and proline contents as well as grain yield. Higher grain yields were obtained with early planting dates under sufficient water supply, whereas superior yields were obtained with delayed planting dates under water stress owing to lower temperatures and evaporation rates. The results suggest that N application could mitigate the adverse effects of drought stress on millet plants by promoting osmoregulation, alleviating lipid peroxidation, and improving plant physiological traits. Foxtail millet had higher antioxidant potential than proso millet, resulting in greater capacity to inhibit production of free oxygen radicals and making it the more drought-tolerant species.

Cover crop mixtures enhance stability but not productivity in a semi‐arid climate

“…This is at least partially due to a high root length density at deeper soil layers (Wendling et al., 2016), which allows it to explore more soil resources and be productive during times of limited precipitation. Foxtail millet and millet species in general are considered drought tolerant (Baltensperger, 1996; Nadeem et al., 2020; Nematpour et al., 2019) due to their highly efficient C4 photosynthetic pathway (Matsuura & An, 2020). Therefore, it is possible that the two grass cover crops used in this study perform better under limited water conditions, thereby producing with more consistency, which appears to be the case for the West site.…”

Microbial Diversity of Upland Rice Roots and Their Influence on Rice Growth and Drought Tolerance

“…Under such circumstances, plant-related microbes that can improve the drought tolerance of crops have attracted increased amounts of attention [ 33 , 49 , 77 , 78 , 79 ]. Scientists have isolated rhizospheric and endophytic bacteria and fungi from arid regions or from xerophytes, and these microbes have been shown to improve the growth of rice, sorghum, corn, cabbage, millet, and wheat under drought-stress conditions [ 14 , 80 , 81 , 82 , 83 , 84 ]. There is abundant evidence that root-associated microbes can help sustain plant growth under drought conditions [ 12 , 18 ].…”

Relationship Between C4Biomass and C4Agriculture During the Holocene and its Implications for Millet Domestication in Northeast China

“…However, the C 4 ecosystem retreated by 2°–3° to lower latitudes during 5.5–4.0 ka. Millet remains almost disappeared in NE China while expanding rapidly in the Yellow River Basin (Hosner et al., 2016), which may be caused by a temperature decrease at the end of Holocene Optimum given that millets are characterized by a high sensitivity to temperature changes (Marcott et al., 2013; Nematpour et al., 2019). The C 4 biomass continued to decrease slightly, but millet reappeared and expanded in NE China after 4.0 ka (Jia et al., 2016).…”