Effects of irrigation on root growth and development of soybean: A 3-year sandy field experiment.

Increasing the water use efficiency of crops is an important agricultural goal closely related to the root system -the primary plant organ for water and nutrient acquisition. In an attempt to evaluate the response of root growth and development of soybean to water supply levels, 200 genotypes were grown in a sandy field for 3 years under irrigated and non-irrigated conditions, and 14 root traits together with shoot fresh weight and plant height were investigated. Three-way ANOVA revealed a significant effect of treatments and years on growth of plants, accounting for more than 80% of the total variability.

Characterization of E93 in neometabolous thrips Frankliniella occidentalis and Haplothrips brevitubus.

Insect metamorphosis into an adult occurs after the juvenile hormone (JH) titer decreases at the end of the juvenile stage. This generally coincides with decreased transcript levels of JH-response transcription factors Krüppel homolog 1 (Kr-h1) and broad (br), and increased transcript levels of the adult specifier E93. Thrips (Thysanoptera) develop through inactive and non-feeding stages referred to as "propupa" and "pupa", and this type of distinctive metamorphosis is called neometaboly.

Ovicidal activity of juvenile hormone mimics in the bean bug, .

Insect juvenile hormone (JH) mimics (JHMs) are known to have ovicidal effects if applied to adult females or eggs. Here, we examined the effects of exogenous JHMs on embryonic development of the bean bug, . The expression profiles of JH early response genes and JH biosynthetic enzymes indicated that JH titer was low for the first 3 days of the egg stage and increased thereafter.

Atypical insects: molecular mechanisms of unusual life history strategies.

Metamorphosis undeniably shaped the evolutionary success of winged insects. So far, what we know about the hormonal regulation and molecular mechanisms controlling insect metamorphosis lies on the understanding of complete and incomplete metamorphosis. Rarer types of metamorphosis are overlooked, yet they could provide important insights as they represent deviations in life history strategies that are associated with unique ecological traits.

Involvement of the transcription factor E75 in adult cuticular formation in the red flour beetle Tribolium castaneum.

Insect adult metamorphosis generally proceeds with undetectable levels of juvenile hormone (JH). In adult development of the red flour beetle Tribolium castaneum, biosynthesis of adult cuticle followed by its pigmentation and sclerotization occurs, and dark coloration of the cuticle becomes visible in pharate adults. Here, we examined the molecular mechanism of adult cuticular formation in more detail.

Sex-specific expression profiles of ecdysteroid biosynthesis and ecdysone response genes in extreme sexual dimorphism of the mealybug Planococcus kraunhiae (Kuwana).

Insect molting hormone (ecdysteroids) and juvenile hormone regulate molting and metamorphic events in a variety of insect species. Mealybugs undergo sexually dimorphic metamorphosis: males develop into winged adults through non-feeding, pupa-like stages called prepupa and pupa, while females emerge as neotenic wingless adults. We previously demonstrated, in the Japanese mealybug Planococcus kraunhiae (Kuwana), that the juvenile hormone titer is higher in males than in females at the end of the juvenile stage, which suggests that juvenile hormone may regulate male-specific adult morphogenesis.

Methoprene-tolerant is essential for embryonic development of the red flour beetle Tribolium castaneum.

Insect juvenile hormone (JH) is well known to regulate post-embryonic development and reproduction in concert with ecdysteroids in a variety of insect species. In contrast, our knowledge on the role of JH in embryonic development is limited and inconsistent. Preceding studies indicate that JH biosynthesis or JH signaling genes are dispensable in holometabolous Drosophila melanogaster and Bombyx mori, while essential in hemimetabolous Blattella germanica.

Development of the Mitsucal computer system to identify causal mutation with a high-throughput sequencer.

Development of Mitsucal. Recent advances in DNA sequencing technology have facilitated whole-genome sequencing of mutants and variants. However, the analyses of large sequence datasets using a computer remain more difficult than operating a sequencer.

Jasmonic acid facilitates flower opening and floral organ development through the upregulated expression of SlMYB21 transcription factor in tomato.

Plants coordinate the timing of flower opening with pollen and gynoecium maturation to achieve successful pollination. However, little is known about how the coordination is executed. We found that flower bud development was paused immediately before flower opening in a jasmonic acid (JA)-insensitive tomato mutant, jai1-1.

Benzoylurea resistance in western flower thrips (Thysanoptera: Thripidae): the presence of a point mutation in .

We examined the susceptibility of field strains (BO-1, BO-2, TO-1, and YH-1) and one laboratory strain (H-1) of the western flower thrip, , to benzoylureas. LC values of novaluron were determined as 0.64 ppm against laboratory strain and 2.

Long-distance peptide signaling essential for nutrient homeostasis in plants.

Organ-to-organ communication is indispensable for higher organisms to maintain homeostasis over their entire life. Recent findings have uncovered that plants, like animals, mediate organ-to-organ communication by long-distance signaling through the vascular system. In particular, xylem-mobile secreted peptides have attracted much attention as root-to-shoot long-distance signaling molecules in response to fluctuating environmental nutrient status.

Identification of three LRR-RKs involved in perception of root meristem growth factor in Arabidopsis.

A peptide hormone, root meristem growth factor (RGF), regulates root meristem development through the PLETHORA (PLT) stem cell transcription factor pathway, but it remains to be uncovered how extracellular RGF signals are transduced to the nucleus. Here we identified, using a combination of a custom-made receptor kinase (RK) expression library and exhaustive photoaffinity labeling, three leucine-rich repeat RKs (LRR-RKs) that directly interact with RGF peptides in Arabidopsis These three LRR-RKs, which we named RGFR1, RGFR2, and RGFR3, are expressed in root tissues including the proximal meristem, the elongation zone, and the differentiation zone. The triple rgfr mutant was insensitive to externally applied RGF peptide and displayed a short root phenotype accompanied by a considerable decrease in meristematic cell number.

WASP-ASSOCIATED FACTORS ACT IN INTERSPECIES COMPETITION DURING MULTIPARASITISM.

Coexistence or displacement of parasitoids in hosts during intrinsic competitive interactions between different parasitoid species (multiparasitism) may depend on their life history traits and behavior. Intense competition for possession of hosts may lead to the elimination of the inferior competitor through physical attack and/or physiological suppression. However, the mechanisms of physiological suppression during multiparasitism remain unclear.

Expressional and functional analysis of CYP15A1, a juvenile hormone epoxidase, in the red flour beetle Tribolium castaneum.

Juvenile hormone (JH) is synthesized and secreted by the corpora allata. In the final two steps of JH biosynthesis, farnesoic acid (FA) is converted to JH through methylation by JH acid O-methyltransferase (JHAMT) and epoxidation by the cytochrome P450 enzyme CYP15. In the present study, we identified a homolog of CYP15 from the red flour beetle Tribolium castaneum (TcCYP15A1), and analyzed its expression as well as its role in JH biosynthesis.

Perception of root-derived peptides by shoot LRR-RKs mediates systemic N-demand signaling.

Nitrogen (N) is a critical nutrient for plants but is often distributed unevenly in the soil. Plants therefore have evolved a systemic mechanism by which N starvation on one side of the root system leads to a compensatory and increased nitrate uptake on the other side. Here, we study the molecular systems that support perception of N and the long-distance signaling needed to alter root development.

A novel type of hemocytes localizing melanization with high-spreading behavior in Mythimna separata.

Lepidopteran larvae show a cellular response to invading foreign substances that are larger than hemocytes, for example, parasitoid eggs or larvae. This response is called hemocyte encapsulation and is often accompanied by phenoloxidase (PO)-catalyzed melanization. In the present study, we artificially transplanted endoparasitoid larvae and small glass fragments into the hemocoel of the common armyworm, Mythimna separata.

Developmental profile and hormonal regulation of the transcription factors broad and Krüppel homolog 1 in hemimetabolous thrips.

In holometabolous insects, Krüppel homolog 1 (Kr-h1) and broad (br) are key players in the juvenile hormone (JH) regulation of metamorphosis: Kr-h1 is an early JH-response gene, while br is a transcription factor that directs pupal development. Thrips (Thysanoptera) are classified as hemimetabolous insects that develop directly from nymph to adult, but they have quiescent and non-feeding stages called propupa and pupa. We analyzed the developmental profiles of br and Kr-h1 in the western flower thrips Frankliniella occidentalis (Thripidae) that has one propupal instar and one pupal instar, and Haplothrips brevitubus (Phlaeothripidae) that has one propupal instar and two pupal instars, i.

Post-translational modifications in secreted peptide hormones in plants.

More than a dozen secreted peptides are now recognized as important hormones that coordinate and specify cellular functions in plants. Recent evidence has shown that secreted peptide hormones often undergo post-translational modification and proteolytic processing, which are critical for their function. Such 'small post-translationally modified peptide hormones' constitute one of the largest groups of peptide hormones in plants.

Secreted peptide signals required for maintenance of root stem cell niche in Arabidopsis.

Stem cells are maintained in the niche by intercellular interactions and signaling networks. In this work, we study extracellular signals required for maintenance of the root stem cell niche in higher plants. We identify a family of functionally redundant homologous peptides that are secreted, tyrosine-sulfated, and expressed mainly in the stem cell area and the innermost layer of central columella cells.

Arabinosylated glycopeptide hormones: new insights into CLAVATA3 structure.

Secreted peptides are now recognized as important members of hormones that coordinate and specify cellular functions in plants. Recent accumulating evidence shows that secreted peptide hormones are often post-translationally modified, and such modification is critical for their function. In this review, we highlight hydroxyproline arabinosylation, which has been found in several peptide hormones including CLAVATA3 (CLV3), a key peptide controlling stem cell renewal and differentiation in Arabidopsis shoot apical meristem.

A link among DNA replication, recombination, and gene expression revealed by genetic and genomic analysis of TEBICHI gene of Arabidopsis thaliana.

Spatio-temporal regulation of gene expression during development depends on many factors. Mutations in Arabidopsis thaliana TEBICHI (TEB) gene encoding putative helicase and DNA polymerase domains-containing protein result in defects in meristem maintenance and correct organ formation, as well as constitutive DNA damage response and a defect in cell cycle progression; but the molecular link between these phenotypes of teb mutants is unknown. Here, we show that mutations in the DNA replication checkpoint pathway gene, ATR, but not in ATM gene, enhance developmental phenotypes of teb mutants, although atr suppresses cell cycle defect of teb mutants.

Identification of tyrosylprotein sulfotransferase in Arabidopsis.

Tyrosine sulfation is a posttranslational modification common in peptides and proteins synthesized by the secretory pathway in most eukaryotes. In plants, this modification is critical for the biological activities of a subset of peptide hormones such as PSK and PSY1. In animals, tyrosine sulfation is catalyzed by Golgi-localized type II transmembrane proteins called tyrosylprotein sulfotransferases (TPSTs).

Eighteen microsatellite loci in Salix arbutifolia (Salicaceae) and cross-species amplification in Salix and Populus species.

Salix arbutifolia is a riparian dioecious tree species that is of conservation concern in Japan because of its highly restricted distribution. Eighteen polymorphic loci of dinucleotide microsatellites were isolated and characterized. Among these, estimates of the expected heterozygosity ranged from 0.