Genome-Wide Differential DNA Methylation and miRNA Expression Profiling Reveals Epigenetic Regulatory Mechanisms Underlying Nitrogen-Limitation-Triggered Adaptation and Use Efficiency Enhancement in Allotetraploid Rapeseed.

Improving crop nitrogen (N) limitation adaptation (NLA) is a core approach to enhance N use efficiency (NUE) and reduce N fertilizer application. Rapeseed has a high demand for N nutrients for optimal plant growth and seed production, but it exhibits low NUE. Epigenetic modification, such as DNA methylation and modification from small RNAs, is key to plant adaptive responses to various stresses.

Balance between nitrogen use efficiency and cadmium tolerance in Brassica napus and Arabidopsis thaliana.

The transmembrane transport of NO and Cd into plant cell vacuoles relies on the energy from their tonoplast proton pumps, V-ATPase and V-PPase. If the activity of these pumps is reduced, it results in less NO and Cd being transported into the vacuoles, which contributes to better nitrogen use efficiency (NUE) and lower Cd tolerance in plants. The physiological mechanisms that regulate the balance between NUE and Cd tolerance remain unknown.

Integrated physiologic, genomic and transcriptomic strategies involving the adaptation of allotetraploid rapeseed to nitrogen limitation.

Background: Nitrogen (N) is a macronutrient that is essential for optimal plant growth and seed yield. Allotetraploid rapeseed (AACC, 2n = 4x = 38) has a higher requirement for N fertilizers whereas exhibiting a lower N use efficiency (NUE) than cereal crops. N limitation adaptation (NLA) is pivotal for enhancing crop NUE and reducing N fertilizer use in yield production.

Effective Genomic Selection in a Narrow-Genepool Crop with Low-Density Markers: Asian Rapeseed as an Example.

Genomic selection (GS) has revolutionized breeding for quantitative traits in plants, offering potential to optimize resource allocation in breeding programs and increase genetic gain per unit of time. Modern high-density single nucleotide polymorphism (SNP) arrays comprising up to several hundred thousand markers provide a user-friendly technology to characterize the genetic constitution of whole populations and for implementing GS in breeding programs. However, GS does not build upon detailed genotype profiling facilitated by maximum marker density.

Genomics-Assisted Identification and Characterization of the Genetic Variants Underlying Differential Nitrogen Use Efficiencies in Allotetraploid Rapeseed Genotypes.

Nitrogen (N) is a non-mineral macronutrient essential for plant growth and development. Oilseed rape (AACC, 2 = 4 = 38) has a high requirement for N nutrients whereas showing the lowest N use efficiency (NUE) among crops. The mechanisms underlying NUE regulation in remain unclear because of genome complexity.

[Multifractal Analysis of Rapeseed Spectrum for Chlorophyll Diagnosis Modeling].

One of the most important topics in crop information science is how to make use of the crop’s information for non-destructive nutrient diagnosis which can be solved with spectrum analysis. The canopy’s spectrum feature is a key indicator to describe the nutritional status for the rapeseeds. The original spectrum is to be disturbed with external factors such as environment and climate; however, it is difficult to be directly used for rapeseed biomass diagnosis due to its huge fluctuation.

Effects of a controlled-release fertilizer on yield, nutrient uptake, and fertilizer usage efficiency in early ripening rapeseed (Brassica napus L.).

Background: Nitrogen (N), phosphorous (P), and potassium (K) are critical nutrient elements necessary for crop plant growth and development. However, excessive inputs will lead to inefficient usage and cause excessive nutrient losses in the field environment, and also adversely affect the soil, water and air quality, human health, and biodiversity.

Methods: Field experiments were conducted to study the effects of controlled-release fertilizer (CRF) on seed yield, plant growth, nutrient uptake, and fertilizer usage efficiency for early ripening rapeseed (Xiangzayou 1613) in the red-yellow soil of southern China during 2011-2013.

[Effects of nitrogen application on yield and nitrogen use efficiency of rapeseed (Brassica napus)].

A greenhouse pot experiment was conducted to study the effects of nitrogen application on the yield and nitrogen use efficiency of rapeseed under post anthesis waterlogging condition. Two high nitrogen use efficiency rapeseed genotypes 'Monty' and 'Xiangyou 15' and two low nitrogen use efficiency rapeseed genotypes 'R210' and 'Bin270' were treated with 3 nitrogen levels (0.05, 0.

Nitrogen Use Efficiency Is Mediated by Vacuolar Nitrate Sequestration Capacity in Roots of Brassica napus.

Enhancing nitrogen use efficiency (NUE) in crop plants is an important breeding target to reduce excessive use of chemical fertilizers, with substantial benefits to farmers and the environment. In Arabidopsis (Arabidopsis thaliana), allocation of more NO3 (-) to shoots was associated with higher NUE; however, the commonality of this process across plant species have not been sufficiently studied. Two Brassica napus genotypes were identified with high and low NUE.

[Effect of atmospheric CO2 concentration and nitrogen application level on absorption and transportation of nutrient elements in oilseed rape].

Effect of elevated atmospheric-CO2 (780 µmol . mol-1) on the absorption and transportation of secondary nutrient elements (calcium, magnesium, sulphur) and micronutrient elements (iron, manganese, zinc, molybdenum and boron) in oilseed rape at the stem elongation stage were studied by greenhouse simulated method. Compared with the ambient CO2 condition, the content of Zn in stem was increased and the contents of other nutrient elements were decreased under the elevated atmospheric-CO2 with no nitrogen (N) application; the contents of Ca, S, B and Zn were increased, and the contents of Mg, Mn, Mo and Fe were decreased under the elevated atmospheric CO2 with N application (0.

[Sn-glycerol-3-phosphate acyltransferases (GPATs) in plants].

Sn-glycerol-3-phosphate acyltransferase (GPAT) catalyzes the acylation at sn-1 position of glycerol-3-phosphate to produce lysophosphatidic acid (LPA) in an acyl-CoA or acyl-ACP-dependent manner, which is the initial and rate-determining step of TAG biosynthetic pathway. Some GPATs have sn-2 transfer activity. Part members of the GPAT gene family have been cloned from different plant species.

[Effects of chemical ripeners on chlorophyll content and antioxidant enzyme activities of rapeseed pod].

A field experiment was conducted to study the effects of ripeners Diguat and Roundup on the chlorophyll content, activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), cell membrane permeability, and malondialdehyde (MDA) content of rapeseed pods. Under effects of Diquat, the chlorophyll content decreased, while the activities of SOD, POD, and CAT, cell membrane permeability, and MDA content increased significantly, leading to the peroxidation of membrane lipid. These effects increased with increasing Diquat concentration.

[Molecular mapping and identification of quantitative trait loci for yield components in rapeseed (Brasscia napus L.)].

A F2 segregating population for genetic map construction and identification of QTL for seed yield in rapeseed (Brassica napus L.), was developed via crossing a conventional rapeseed line 04-1139 with a high yielding multiple silique rapeseed line 05-1054. A genetic map including 19 linkage groups was constructed with 200 SSR (Simple sequence repeat) and SRAP (Sequence-related amplified polymorphism) markers.

[Key enzymes in starch synthesis in plants].

Starch, the most common form of stored carbon in plants, is both the major food source for mankind and important raw material for many industries. It is composed of two types of alpha-1,4-linked glucan polymer: essentially unbranched amylose and regularly branched amylopectin, and synthesized in photosynthetic and non-photosynthetic organs. Starch is synthesized via four committed enzyme steps: ADP-Glc pyrophosphorylase, which synthesizes sugar nucleotide precursors; starch synthase, which extends the alpha-1,4-linked glucan chains using ADP-Glc; starch-branching enzymes, which introduce alpha-1,6 branch points to form amylopectin; and starch debranching enzymes, which hydrolyze alpha-1,6 branches in glucans.