Endosperm

Flowering plants, also known as angiosperms, emerged approximately 150 to 200 million years ago. Since then, they have undergone rapid and extensive expansion, now encompassing around 90% of all land plant species. The remarkable diversification of this group has been a subject of in-depth investigations, and several evolutionary innovations have been proposed to account for their success. In this primer, we will specifically focus on one such innovation: the advent of seeds containing endosperm.

Limited commercial quality protein maize (QPM) varieties with low grain yield potential are currently grown in Eastern and Southern Africa (ESA). This study was conducted to (i) assess the performance of single-cross QPM hybrids that were developed from elite inbred lines using line-by-tester mating design and (ii) estimate the general (GCA) and specific (SCA) combining ability of the QPM inbred lines for grain yield, agronomic and protein quality traits. One hundred and six testcrosses and four checks were evaluated across six environments in ESA during 2015 and 2016...

Palm seedlings are visually selected from mature fruits in a slow process that leads to nonuniform germination and high embryo mortality. In this study, we determined the levels of monosaccharides, their crystallinity, and their role in the formation of Euterpe edulis endosperm during seed maturation. Seeds harvested from 108 to 262 days after anthesis (DAA) were analyzed morphologically, physiologically, and chemically to measure soluble and insoluble lignins, ashes, structural carbohydrates, degree of crystallinity, and endo-β-mannanase...

Cereal grains are an important source of food and feed. To provide comprehensive spatiotemporal information about biological processes in developing seeds of cultivated barley (Hordeum vulgare L. subsp. vulgare), we performed a transcriptomic study of the embryo, endosperm, and seed maternal tissues collected from grains 4-32 days after pollination. Weighted gene co-expression network and motif enrichment analyses identified specific groups of genes and transcription factors (TFs) potentially regulating barley seed tissue development...

The conversion of raw barley ( Hordeum vulgare L.) to malt requires a process of controlled germination, where the grain is submerged in water to raise the moisture content to >40%. The transmembrane proteins, aquaporins, influence water uptake during the initial stage of controlled germination, yet little is known of their involvement in malting. With the current focus on sustainability, understanding the mechanisms of water uptake and usage during the initial stages of malting has become vital in improving efficient malting practices...

Endosperm is the main storage organ in cereal grain and determines grain yield and quality. The molecular mechanisms of heat shock proteins in regulating starch biosynthesis and endosperm development remain obscure. Here, we report a rice floury endosperm mutant flo24 that develops abnormal starch grains in the central starchy endosperm cells. Map-based cloning and complementation test showed that FLO24 encodes a heat shock protein HSP101, which is localized in plastids. The mutated protein FLO24T296I dramatically lost its ability to hydrolyze ATP and to rescue the thermotolerance defects of the yeast hsp104 mutant...

Modification of silent latent endosperm-enabled promoters (SLEEPERs) allows the ectopic activation of non-expressed metabolic genes in rice callus Metabolic engineering in plants typically involves transgene expression or the mutation of endogenous genes. An alternative is promoter modification, where small changes in the promoter sequence allow genes to be switched on or off in particular tissues. To activate silent genes in rice endosperm, we screened native promoters for near-miss cis-acting elements that can be converted to endosperm-active regulatory motifs...

During maize endosperm filling, sucrose not only serves as a source of carbon skeletons for storage-reserve synthesis, but also acts as a stimulus to promote this process. However, the molecular mechanism details about sucrose and endosperm filling are poorly understood. Here, we found that sucrose promoted the expression of endosperm-filling hub Opaque2 (O2), coordinating with storage-reserve accumulation. A protein kinase called SnRK1a1 attenuated O2-mediated transactivation, but sucrose released the suppression...

Kopyor is a coconut with unique characteristics from Indonesia, one of the largest coconut producers in the world. Kopyor is an edible mature coconut with soft endosperm. Although this fruit is one of the most popular coconuts in the world, there are limited studies on its properties, including its sensory attributes and metabolite profiles. This study investigates the characteristics of kopyor using sensory evaluation, a widely targeted metabolomics approach, and multivariate analysis. The liquid (water) and solid (flesh) endosperms were collected as the samples...

Protein disulfide isomerase (PDI, EC 5.3.4.1) is a thiol-disulfide oxidoreductase that plays a crucial role in catalyzing the oxidation and rearrangement of disulfides in substrate proteins. In plants, PDI is primarily involved in regulating seed germination and development, facilitating the oxidative folding of storage proteins in the endosperm, and also contributing to the formation of pollen. However, the role of PDI in root growth has not been previously studied. This research investigated the impact of PDI gene deficiency in plants by using 16F16 [2-(2-Chloroacetyl)-2,3,4,9-tetrahydro-1-methyl-1H-pyrido[3,4-b]indole-1-carboxylic acid methyl ester], a small-molecule inhibitor of PDI, to remove functional redundancy...

The male sterility line is a vital approach in the genetic breeding of sorghum. The husking process affects the grain's nutritional composition, emphasizing the intricate relationship between genetic enhancement and dietary requirements. The current study assessed the influence of the Husking Fraction Time Unit (HFTU) process, which was set at 30 (S) and 80 (S) time units per second (S). The study assessed the impact of the (HFTU) process on fifty-one inbred line sorghum race varieties, which implied diverse nutritional profiles considering the pericarp color variations...

The quantity and composition of rice proteins play a crucial role in determining taste quality of sake, Japanese rice wine. However, the spatial distribution of proteins within rice grains, especially in endosperm tissue, and the differences between rice varieties remain unclear. Here, we analyzed the crude protein contents and composition ratios of table (Nipponbare and Koshihikari) and genuine sake rice varieties (Yamadanishiki, Gohyakumangoku, Dewasansan, Dewanosato, and Yumenokaori) to elucidate their spatial distribution within the Japonica rice grain endosperm...

The early development of the endosperm is crucial for balancing the allocation of maternal nutrients to offspring. This process is believed to be evolutionarily associated with genomic imprinting, resulting in parentally biased allelic gene expression. Beyond FIS (Fertilization Independent Seed) genes, the number of imprinted genes involved in early endosperm development and seed size determination remains limited. This study introduces two early endosperm-expressed ICF1 and ICF2, as maternally expressed imprinted genes (MEGs)...

Transitory starch is an important carbon source in leaves, and its biosynthesis and metabolism are closely related to grain yield and quality. The molecular mechanisms controlling leaf transitory starch biosynthesis and degradation and their effects on rice (Oryza sativa) yield and quality are unclear. Here, we showed that OsLESV and OsESV1, the rice orthologs of AtLESV and AtESV1, are associated with transitory starch biosynthesis in rice. The total starch and amylose contents in leaves and endosperm were significantly reduced, and the final grain quality and yield were compromised in oslesv and osesv1 single and oslesv esv1 double mutants...

Plant-based adhesives, such as those made from wheat, have been prominently used for books and paper-based objects and are also used as conservation adhesives. Starch paste originates from starch granules, whereas flour paste encompasses the entire wheat endosperm proteome, offering strong adhesive properties due to gluten proteins. From a conservation perspective, understanding the precise nature of the adhesive is vital as the longevity, resilience, and reaction to environmental changes can differ substantially between starch- and flour-based pastes...

Doubled haploid (DH) technology provides an effective way to generate homozygous genetic and breeding materials over a short period of time. We produced three types of homozygous TtMTL gene-edited mutants ( mtl-a , mtl-b , and mtl-ab ) by CRISPR/Cas9 in durum wheat. PCR restriction enzymes and sequencing confirmed that the editing efficiency was up to 53.5%. The seed-setting rates of the three types of mutants ranged from 20% to 60%. Abnormal grain phenotypes of kernel, embryo, and both embryo and endosperm abortions were observed in the progenies of the mutants...

INTRODUCTION: Paphiopedilum barbigerum is currently the rarest and most endangered species of orchids in China and has significant ornamental value. The mature seeds of P. barbigerum are difficult to germinate owing to the absence of an endosperm and are highly dependent on mycorrhizal fungi for germination and subsequent development. However, little is known about the regulation mechanisms of symbiosis and symbiotic germination of P. barbigerum seeds. METHODS: Herein, transcriptomics and proteomics were used to explore the changes in the P...

A non-Kranz C4 photosynthesis of the NAD-ME subtype, specifically in developing wheat grains (14 dpa, days post-anthesis) was originally demonstrated using transcriptome-based RNA-seq. Here we present a re-examination of evidence for C4 photosynthesis in the developing grains of wheat and, more broadly, the Pooideae and an investigation of the evolutionary processes and implications. The expression profiles for the genes associated with C4 photosynthesis (C4 - and C3 -specific) were evaluated using published transcriptome data for the outer pericarp, inner pericarp, and endosperm tissues of the developing wheat grains...

Harder kernels of barley are regarded as one of the factors that restrict water and enzyme movement within the endosperm during malting. A comprehensive study of two domestic varieties was performed for evaluating malting quality. Both β-glucan and total protein content of the Chinese domestic barley (Ganpi-6 and Kenpi-14) were significantly higher than Copeland. Grain hardness of the Chinese domestic barley was higher and water uptake ratio was lower compared with the Copeland. During germination, the expression levels of NCED1, NCED2 (major key regulatory enzymes for abscisic acid biosynthesis genes) were higher, whereas gibberelic acid (GA) synthesis genes (GA20ox1, GA2ox3, GA3ox2) were lower in the Ganpi-6, Kenpi-14 compared with Copeland...

ADP-glucose pyrophosphorylase plays a pivotal role as an allosteric enzyme, essential for starch biosynthesis in plants. The higher plant AGPase comparises of a pair of large and a pair of small subunits to form a heterotetrameric complex. Growing evidence indicates that each subunit plays a distinct role in regulating the underlying mechanism of starch biosynthesis. In the rice genome, there are four large subunit genes (OsL1-L4) and three small subunit genes (OsS1, OsS2a, and OsS2b). While the structural assembly of cytosolic rice AGPase subunits (OsL2:OsS2b) has been elucidated, there is currently no such documented research available for plastidial rice AGPases (OsL1:OsS1)...