Association mapping of starch chain length distribution and amylose content in pea (Pisum sativum L.) using carbohydrate metabolism candidate genes

The mediation mechanism of calcium ions on black bean type 3 resistant starch: Metabolomics, structure characteristics and digestibility

The type 3 resistant starch (RS3) is beneficial for blood glucose management. A high quality RS3 was provided and its formation mechanism after calcium ion (Ca2+) treatment was investigated in this study. The metabolomics, structure and digestion properties were evaluated. Metabolomics was performed by untargeted UHPLC-Q-TOF/MS, and a total of 11 significantly different metabolites was found. The NMR, ATR-FTIR, and XRD results showed that the degree of double helix decreased from 5.34 to 1.07, crystallinity decreased from 33.58 % to 19.88 %, and the amorphous region increased from 69.76 % to 78.33 %. Large particle polymers were observed by SEM on the granule surface of starch with Ca2+ treatment. Digestion test showed that Ca2+ increased the RS3 from 9.70 % to 22.26 %. The result indicated that Ca2+ induced the formation of chelates between Ca2+ and -OH, promoted the RS3 content and regulated carbohydrate metabolism. The study provided theoretical basis for producing low-glycemic black bean foods.

Biobased composites from agro-industrial wastes and by-products

The greater awareness of non-renewable natural resources preservation needs has led to the development of more ecological high-performance polymeric materials with new functionalities. In this regard, biobased composites are considered interesting options, especially those obtained from agro-industrial wastes and by-products. These are low-cost raw materials derived from renewable sources, which are mostly biodegradable and would otherwise typically be discarded. In this review, recent and innovative academic studies on composites obtained from biopolymers, natural fillers and active agents, as well as green-synthesized nanoparticles are presented. An in-depth discussion of biobased composites structures, properties, manufacture, and life-cycle assessment (LCA) is provided along with a wide up-to-date overview of the most recent works in the field with appropriate references. Potential uses of biobased composites from agri-food residues such as active and intelligent food packaging, agricultural inputs, tissue engineering, among others are described, considering that the specific characteristics of these materials should match the proposed application.

Understanding Starch Metabolism in Pea Seeds towards Tailoring Functionality for Value-Added Utilization

Starch is the most abundant storage carbohydrate and a major component in pea seeds, accounting for about 50% of dry seed weight. As a by-product of pea protein processing, current uses for pea starch are limited to low-value, commodity markets. The globally growing demand for pea protein poses a great challenge for the pea fractionation industry to develop new markets for starch valorization. However, there exist gaps in our understanding of the genetic mechanism underlying starch metabolism, and its relationship with physicochemical and functional properties, which is a prerequisite for targeted tailoring functionality and innovative applications of starch. This review outlines the understanding of starch metabolism with a particular focus on peas and highlights the knowledge of pea starch granule structure and its relationship with functional properties, and industrial applications. Using the currently available pea genetics and genomics knowledge and breakthroughs in omics technologies, we discuss the perspectives and possible avenues to advance our understanding of starch metabolism in peas at an unprecedented level, to ultimately enable the molecular design of multi-functional native pea starch and to create value-added utilization.

Identification of Candidate Gene-Based Markers for Girth Growth in Rubber Trees

Girth growth is an important factor in both latex and timber production of the rubber tree. In this study, we performed candidate gene association mapping for girth growth in rubber trees using intron length polymorphism markers (ILP) in identifying the candidate genes responsible for girth growth. The COBL064_1 marker developed from the candidate gene (COBL4) regulating cellulose deposition and oriented cell expansion in the plant cell wall showed the strongest association with girth growth across two seasons in the Amazonian population and was validated in the breeding lines. We then applied single molecule real-time (SMRT) circular consensus sequencing (CCS) to analyze a wider gene region of the COBL4 to pinpoint the single nucleotide polymorphism (SNP) that best explains the association with the traits. A SNP in the 3’ UTR showing linkage disequilibrium with the COBL064_1 most associated with girth growth. This study showed that the cost-effective method of ILP gene-based markers can assist in identification of SNPs in the candidate gene associated with girth growth. The SNP markers identified in this study added useful markers for the improvement of girth growth in rubber tree breeding programs.

Synthesis and characterization of starch based bioplatics using varying plant-based ingredients, plasticizers and natural fillers

With the ever-increasing demand of plastics in the world and their consequent disastrous effects on environment, a suitable environmental-friendly substitute like bioplastics/biodegradable plastics is the need time. This study centers on green-production of a variety of bioplastic samples from (1) banana peel starch (BPP) and (2) a composite of banana peel starch, cornstarch and rice starch (COM) with varying amounts of potato peel powder and wood dust powder as fillers, respectively. Two different plasticizers - Glycerol and Sorbitol - have been utilized separately and in a 1:1 combination. A total of 12 samples of each of two types of bioplastics were made using multiple amounts and combinations of the fillers and plasticizers, to test the differences in the physical and chemical characteristics (moisture content, absorption of water, solubility in water, solubility in alcohol, biodegradation in soil, tensile strength, Young's modulus and FT-IR) of the produced samples due to their different compositions. The differences in the properties of the bioplastic samples produced make them suitable for usage in many different applications. All 24 of the samples produced were synthesized using natural and environmentally safe raw material and showed biodegradation, thus proving to be a good alternative to the conventional plastics.

Candidate gene association of gene expression data in sugarcane contrasting for sucrose content

Association mapping of gene expression data, generated from transcriptome and proteome studies, provides a means of understanding the functional significance and trait association potential of candidate genes. In this study, we applied candidate gene association mapping to validate sugarcane genes, using data from the starch and sucrose metabolism pathway, transcriptome, and proteome. We performed multiplex PCR targeted amplicon sequencing of 109 candidate genes, using NGS technology. A range of statistical models, both single-locus and multi-locus, were compared for minimization of false positives in association mapping of four sugar-related traits with different heritability. The Fixed and random model Circulating Probability Unification model effectively suppressed false positives for both low- and high-heritability traits. We identified favorable alleles of the candidate genes involved in signalling and transcriptional regulation. The results will support genetic improvement of sugarcane and may help clarify the genetic architecture of sugar-related traits.

Retrotransposons and the Evolution of Genome Size in Pisum

Here we investigate the plant population genetics of retrotransposon insertion sites in pea to find out whether genetic drift and the neutral theory of molecular evolution can account for their abundance in the pea genome. (1) We asked whether two contrasting types of pea LTR-containing retrotransposons have the frequency and age distributions consistent with the behavior of neutral alleles and whether these parameters can explain the rate of change of genome size in legumes. (2) We used the recently assembled v1a pea genome sequence to obtain data on LTR-LTR divergence from which their age can be estimated. We coupled these data to prior information on the distribution of insertion site alleles. (3) We found that the age and frequency distribution data are consistent with the neutral theory. (4) We concluded that demographic processes are the underlying cause of genome size variation in legumes.

Insight Into the Prospects for the Improvement of Seed Starch in Legume-A Review

In addition to proteins and/or oils, mature seeds of most legume crops contain important carbohydrate components, including starches and sugars. Starch is also an essential nutritional component of human and animal diets and has various food and non-food industrial applications. Starch is a primary insoluble polymeric carbohydrate produced by higher plants and consists of amylose and amylopectin as a major fraction. Legume seeds are an affordable source of not only protein but also the starch, which has an advantage of being resistant starch compared with cereal, root, and tuber starch. For these reasons, legume seeds form a good source of resistant starch-rich healthy food with a high protein content and can be utilized in various food applications. The genetics and molecular details of starch and other carbohydrate components are well studied in cereal crops but have received little attention in legumes. In order to improve legume starch content, quality, and quantity, it is necessary to understand the genetic and molecular factors regulating carbohydrate metabolism in legume crops. In this review, we assessed the current literature reporting the genetic and molecular basis of legume carbohydrate components, primarily focused on seed starch content. We provided an overview of starch biosynthesis in the heterotrophic organs, the chemical composition of major consumable legumes, the factors influencing starch digestibility, and advances in the genetic, transcriptomic, and metabolomic studies in important legume crops. Further, we discussed breeding and biotechnological approaches for the improvement of the starch composition in major legume crops. The information reviewed in this study will be helpful in facilitating the food and non-food applications of legume starch and provide economic benefits to farmers and industries.

Ultra-high performance liquid chromatography-size exclusion chromatography (UPLC-SEC) as an efficient tool for the rapid and highly informative characterisation of biopolymers

Starch has a complex molecular structure, with properties dependent on the relative chain lengths and branching structure of its constituent molecules, which varies due to polymorphisms in starch biosynthetic genes, as well as environmental factors. Here we present the application of ultra-high performance size exclusion chromatography to the separation of starch chains from plant seeds. Several methods, have been used to analyse chain length distributions in starch, all with limitations in terms of analysis time, sample preparation and molecular weight range. Here we demonstrate that chain length distributions can be obtained with dramatically reduced analysis time using ultra-high performance size exclusion chromatography. The method may also show improvements in resolution of some fine structural features. Understanding links between starch fine structure and biosynthetic genes will allow bioengineering of starches with tailored properties. This technique may have application to the size separation and resolution of a range of biopolymers of value to the food, drink and pharmaceutical industries.