Enlisting wild grass genes to combat nitrification in wheat farming: a nature-based solution

Active nitrifiers and rapid nitrification are major contributing factors to nitrogen losses in global wheat production. Suppressing nitrifier activity is an effective strategy to limit N losses from agriculture. Production and release of nitrification inhibitors from plant roots is termed “biological nitrification inhibition” (BNI). Here, we report the discovery of a chromosome region that controls BNI production in “wheat grass” Leymus racemosus (Lam.) Tzvelev, located on the short arm of the “Lr#3Nsb” (Lr#n), which can be transferred to wheat as T3BL.3NsbS (denoted Lr#n-SA), where 3BS arm of chromosome 3B of wheat was replaced by 3NsbS of L. racemosus. We successfully introduced T3BL.3NsbS into the wheat cultivar “Chinese Spring” (CS-Lr#n-SA, referred to as “BNI-CS”), which resulted in the doubling of its BNI capacity. T3BL.3NsbS from BNI-CS was then transferred to several elite high-yielding hexaploid wheat cultivars, leading to near doubling of BNI production in “BNI-MUNAL” and “BNI-ROELFS.” Laboratory incubation studies with root-zone soil from field-grown BNI-MUNAL confirmed BNI trait expression, evident from suppression of soil nitrifier activity, reduced nitrification potential, and N2O emissions. Changes in N metabolism included reductions in both leaf nitrate, nitrate reductase activity, and enhanced glutamine synthetase activity, indicating a shift toward ammonium nutrition. Nitrogen uptake from soil organic matter mineralization improved under low N conditions. Biomass production, grain yields, and N uptake were significantly higher in BNI-MUNAL across N treatments. Grain protein levels and breadmaking attributes were not negatively impacted. Wide use of BNI functions in wheat breeding may combat nitrification in high N input-intensive farming but also can improve adaptation to low N input marginal areas.

Bibliographic Details

Main Authors:	Guntur Venkata Subbarao, Kishii, M., Bozal-Leorri, A., Ortiz-Monasterio, I., Xiang Gao, Ibba, M.I., Karwat, H., Gonzalez-Moro, M.B., Gonzalez-Murua, C., Tadashi Yoshihashi, Tobita, S., Kommerell, V., Braun, H.J., Iwanaga, M.
Format:	Article biblioteca
Language:	English
Published:	National Academy of Sciences 2021
Subjects:	AGRICULTURAL SCIENCES AND BIOTECHNOLOGY, Nitrification Inhibition, Nitrogen Pollution, Biological Nitrification Inhibition, NITROGEN, POLLUTION, NITRIFICATION INHIBITORS, GENETIC IMPROVEMENT, WHEAT,
Online Access:	https://hdl.handle.net/10883/21645
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