A Comparative Study of Ethylene Emanation upon Nitrogen Deficiency in Natural Accessions of Arabidopsis thaliana

Abstract

An original approach to develop sustainable agriculture with less nitrogen fertilizer inputs is to tackle the cross-talk between nitrogen nutrition and plant growth regulators. In particular the gaseous hormone, ethylene, is a prime target for that purpose. The variation of ethylene production in natural accessions of the model species Arabidopsis thaliana was explored in response to the nitrate supply. Ethylene was measured with a laser-based photoacoustic detector. First, experimental conditions were established with Columbia-0 (Col-0) accession, which was grown in vitro on horizontal plates across a range of five nitrate concentrations (0.5, 1, 2.5, 5, or 10 mM). The concentrations of 1 and 10 mM nitrate were retained for further characterization. Along with a decrease of total dry biomass and higher biomass allocation to the roots, the ethylene production was 50% more important at 1 mM than at 10 mM nitrate. The total transcript levels of 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID SYNTHASES (ACS) in roots and those of ACC OXIDASES (ACO) in shoots increased by 100% between the same treatments. This was mainly due to higher transcript levels of ACS6 and of ACO2 and ACO4 respectively. The assumption was that during nitrogen deficiency, the greater biomass allocation in favor of the roots was controlled by ethylene being released in the shoots after conversion of ACC originating from the roots. Second, biomass and ethylene productions were measured in 20 additional accessions. Across all accessions, the total dry biomass and ethylene production were correlated negatively at 1 mM but positively at 10 mM nitrate. Furthermore, polymorphism was surveyed in ACC and ethylene biosynthesis genes and gene products among accessions. Very few substitutions modifying the amino acids properties in conserved motifs of the enzymes were found in the accessions. Natural variation of ethylene production could be further explored to improve Nitrogen Use Efficiency (NUE), in particular by manipulating features like the biomass production and the timing of senescence upon nitrogen limitation.

Variations in Nitrogen Metabolism are Closely Linked with Nitrogen Uptake and Utilization Efficiency in Cotton Genotypes under Various Nitrogen Supplies

“…The use of crop genotypes to select the ideal form with desirable traits is an effective approach in order to attain high NUE [12]. Significant progress has been made in Arabidopsis, and different accessions have been used for exploiting natural variations in N uptake, utilization, and NUE in response to various N supply [12,13]. Moreover, such approaches also have been applied in crop plants such as rice [14], wheat [15], maize [16], rapeseed [17], tomato [18,19], soybean [20], and barley [21].…”

MORPHOGENESIS AND SECONDARY METABOLITES PRODUCTION IN THE MEDICINAL PLANT Castilleja tenuiflora Benth. UNDER NITROGEN DEFICIENCY AND STARVATION STRESS IN A TEMPORARY IMMERSION SYSTEM

“…When the chlorophylls are degraded, the cells become susceptible to oxidative damage by highlight and other photosynthetic pigments are exposed or the novo synthetized to dissipate excess energy, as anthocyanins (Carpenter et al 2014;Kovinich et al 2014). A decrease in proteins, chlorophylls, appearance of chlorosis and anthocyanin production has been also observed in Arabidopsis thaliana and Solanum lycopersicum under N stress (Larbat et al 2012;De Gernier et al 2016).…”

OsEIL1 protects rice growth under NH4+ nutrition by regulating OsVTC1‐3‐dependent N‐glycosylation and root NH4+ efflux

“…Thus, NH 4 + toxicity in such plants is rare under natural circumstances in well‐aerated soils, explaining the lack of refined adaptations. It has been suggested that AtEIN3 plays a pivotal role in the regulation of nitrate‐use efficiency (De Gernier et al, 2016; J. Wang et al, 2015; Zheng et al, 2013). However, most rice cultivars have traditionally been cultivated under flooded, anaerobic soil conditions (Kirk & Kronzucker, 2000, 2005).…”