Genetic studies of different agronomic, quality and yield contributing traits in Gossypium hirsutum L.

An experiment of 4 × 4 diallel was carried out to study the gene action of different yield and yield contributing traits of four advanced cotton cultivars using Mather and Jinks approach. Significant variation was present for all the characters (P< 0.01). The data on recorded parameters revealed that most of the traits were fully or partially fit for genetic interpretation. Additive gene action (D) was significant and pre-dominant for all the characters while seeds per locule showed dominance effect of H1& H2, and it was confirmed by the value of degree of dominance (H1/D 0.5). The value of H2/4H1 and h2 (measures the direction of dominance) demonstrated asymmetrical division of dominant genes for all traits, except ginning out turn (G.O.T) percentage and fiber length, in parental material. All the studied traits showed high value of narrow sense heritability (h2NS), however seeds per locule possessed low heritability. The genetic analysis revealed that all the characters could be improved by progeny and pedigree selection, whereas hybrid dynamism could be exploited in the trait like seeds per locule.

A simple method for the application of exogenous phytohormones to the grass leaf base protodermal zone to improve grass leaf epidermis development research

Background The leaf epidermis functions to prevent the loss of water and reduce gas exchange. As an interface between the plant and its external environment, it helps prevent damage, making it an attractive system for studying cell fate and development. In monocotyledons, the leaf epidermis grows from the basal meristem that contains protodermal cells. Leaf protoderm zone is covered by the leaf sheath or coleoptile in maize and wheat, preventing traditional exogenous phytohormone application methods, such as directly spraying on the leaf surface or indirectly via culture media, from reaching the protoderm areas directly. The lack of a suitable application method limits research on the effect of phytohormone on the development of grass epidermis. Results Here, we describe a direct and straightforward method to apply exogenous phytohormones to the leaf protoderms of maize and wheat. We used the auxin analogs 2,4-D and cytokinin analogs 6-BA to test the system. After 2,4-D treatment, the asymmetrical division events and initial stomata development were decreased, and the subsidiary cells were induced in maize, the number of GMC (guard mother cell), SMC (subsidiary mother cell) and young stomata were increased in wheat, and the size of the epidermal cells increased after 6-BA treatment in maize. Thus, the method is suitable for the application of phytohormone to the grass leaf protodermal areas. Conclusions The method to apply hormones to the mesocotyls of maize and wheat seedlings is simple and direct. Only a small amount of externally applied substances are needed to complete the procedure in this method. The entire experimental process lasts for ten days generally, and it is easy to evaluate the phytohormones’ effect on the epidermis development.

A simple method for exogenously phytohormone application to the protodermal areas in the base of maize (Zea mays L.) leaf

Background: The maize leaf epidermis is function as protection against water loss and gas exchange, contacting the environment and avoiding the damage, which is an attractive system for studying the process of cell fate and development. In monocots, leaves epidermis grown from basal meristem, which contains protodermal cells. The leaf protoderm zone was covered by the leaf sheath or coleoptile in maize, the classic exogenously phytohormone application method, such as spraying on leaf surface or adding in the culture media can’t apply the phytohormone to the protoderm areas directly, which restricts the research about phytohormone effect epidermal development.Results: Here we described a simple and direct method for exogenously application of phytohormone to maize leaf protoderm. We use the auxin analogs 2,4-D to test the system, and the asymmetrical division events which initial stomata development were decreased and the subsidiary cells were induced in advance after 2,4-D treatment. This result was the same as other similar studies’ results, indicated that the method is suitable for been used for application phytohormone to the maize leaf protodermal areas.Conclusions: The method, applied hormones on the mesocotyls of the maize seedlings, is simple and direct. Only a small amount of externally applied substances is required to complete this experiment through this method. The entire experiment process just last 10 days generally and it is easy to survey the phytohormone's effect on the epidermis development.

The Winner Takes It All: Auxin—The Main Player during Plant Embryogenesis

In plants, the first asymmetrical division of a zygote leads to the formation of two cells with different developmental fates. The establishment of various patterns relies on spatial and temporal gene expression, however the precise mechanism responsible for embryonic patterning still needs elucidation. Auxin seems to be the main player which regulates embryo development and controls expression of various genes in a dose-dependent manner. Thus, local auxin maxima and minima which are provided by polar auxin transport underlie cell fate specification. Diverse auxin concentrations in various regions of an embryo would easily explain distinct cell identities, however the question about the mechanism of cellular patterning in cells exposed to similar auxin concentrations still remains open. Thus, specification of cell fate might result not only from the cell position within an embryo but also from events occurring before and during mitosis. This review presents the impact of auxin on the orientation of the cell division plane and discusses the mechanism of auxin-dependent cytoskeleton alignment. Furthermore, close attention is paid to auxin-induced calcium fluxes, which regulate the activity of MAPKs during postembryonic development and which possibly might also underlie cellular patterning during embryogenesis.

P14.19 The inverse paradigm of IDH-wildtype glioblastoma is fundamental to overcome the two causes of resistance and develop novel effective therapies

BACKGROUND IDH-wildtype glioblastoma behaves differently from all other solid tumors. This is the reason why after decades of praiseworthy therapeutic efforts, the prognosis remains very poor. Many clues (radiological, clinical, surgical) and recent indirect experimental evidence converge to indicate that the entire brain parenchyma is micro-infiltrated from the very beginning by the founding clone before the primary bulk has started its growth. Therefore, only in IDH-wildtype glioblastoma the malignant (i.e. distantly infiltrating the organ of origin) and deadly (leading cause to patient’s death) phases coincide and overlap in one single phase. MATERIALS AND METHODS Appropriate sampling procedures must absolutely take into consideration both the tumor bulk and the micro-infiltrated brain parenchyma. They can be performed (with full respect for ethical issues) analyzing neoplastic and “healthy” material obtained from living patients (a), using animal models (b), studying post-mortem samples from rapid autopsies (c), comparing local and distant recurrences with the primary bulk (d). The study and analysis of the bulk tumor must be carried out by collecting multiple multiregional spatially separated samples throughout the whole tumor mass. The analysis of the micro-infiltrated brain parenchyma in living patients can be performed appropriately and ethically also from surgical patient tissue. RESULTS The phylogenetic tree of the tumor bulk must be inferred and reconstructed by the collection and analysis of multiple regionally separated samples. Additionally, driver and passenger events will be identified as well as the CSCs of samples. The procedures to ethically sample the micro-infiltrated brain parenchyma enable us to collect and identify the founder CSCs which lie quiescent in the perivascular parenchymal niches across the whole brain. Indeed, distant recurrences are due to their activation. CONCLUSION IDH-wildtype glioblastoma is the only brain tumor which arises from astrocyte-like cells of the SVZ ribbon layer and it is able to micro-infiltrate the whole supratentorial brain parenchyma before starting its growth. Its unique inverse paradigm explains the emergence of distant recurrences (sharing only truncal mutations with the primary bulk) and adds, in addition to the heterogeneity of the primary bulk and its residues, a second crucial cause of resistance to take into account (i.e. the founder CSCs which reside quiescent, in G0 state, in the perivascular parenchymal niches). Therefore, innovative therapies must identify and selectively target either CSCs unique properties related to their impaired asymmetrical division or stable driver lesions of the founder CSC (without alternative mutations and pathways) or exclusive markers used by the founder CSCs to settle dormant (involving mechanisms of adhesion, anchorage and cell cycle arrest) in their niches.

Constitutive signaling activity of a receptor-associated protein links fertilization with embryonic patterning inArabidopsis thaliana

In flowering plants, the asymmetrical division of the zygote is the first hallmark of apical-basal polarity of the embryo and is controlled by a MAP kinase pathway that includes the MAPKKK YODA (YDA). InArabidopsis, YDA is activated by the membrane-associated pseudokinase SHORT SUSPENSOR (SSP) through an unusual parent-of-origin effect:SSPtranscripts accumulate specifically in sperm cells but are translationally silent. Only after fertilization is SSP protein transiently produced in the zygote, presumably from paternally inherited transcripts.SSPis a recently diverged, Brassicaceae-specific member of theBRASSINOSTEROID SIGNALING KINASE(BSK) family. BSK proteins typically play broadly overlapping roles as receptor-associated signaling partners in various receptor kinase pathways involved in growth and innate immunity. This raises two questions: How did a protein with generic function involved in signal relay acquire the property of a signal-like patterning cue, and how is the early patterning process activated in plants outside the Brassicaceae family, whereSSPorthologs are absent? Here, we show thatArabidopsis BSK1andBSK2, two close paralogs ofSSPthat are conserved in flowering plants, are involved in several YDA-dependent signaling events, including embryogenesis. However, the contribution of SSP to YDA activation in the early embryo does not overlap with the contributions of BSK1 and BSK2. The loss of an intramolecular regulatory interaction enables SSP to constitutively activate the YDA signaling pathway, and thus initiates apical-basal patterning as soon as SSP protein is translated after fertilization and without the necessity of invoking canonical receptor activation.

A Case of Split Cord Malformation with Triple Bony Spur in a Single Dural Sleeve—A Classification Dilemma

Split cord malformation-I (SCM-I) is characterized by the presence of double dural sacs, with rigid extradural bony/cartilaginous spur leading to symmetrical or asymmetrical division of the cord. In split cord malformation-II (SCM-II), there is a single dural sac with a nonrigid fibrous spur and symmetrical division of the cord. SCM-II are slightly more common than SCM-I, constituting around 50 to 60% of SCMs. The authors report a unique case of SCM with triple bony spurs lying both intra- and extradurally in a single dural sleeve. At the time of submission of this report, to the best of authors’ knowledge, no case of SCM with triple bony spurs in single dural sleeve has been reported anywhere in the world literature.

Mediator subunit MED31 is required for radial patterning of Arabidopsis roots

Stem cell specification in multicellular organisms relies on the precise spatiotemporal control of RNA polymerase II (Pol II)-dependent gene transcription, in which the evolutionarily conserved Mediator coactivator complex plays an essential role. In Arabidopsis thaliana, SHORTROOT (SHR) and SCARECROW (SCR) orchestrate a transcriptional program that determines the fate and asymmetrical divisions of stem cells generating the root ground tissue. The mechanism by which SHR/SCR relays context-specific regulatory signals to the Pol II general transcription machinery is unknown. Here, we report the role of Mediator in controlling the spatiotemporal transcriptional output of SHR/SCR during asymmetrical division of stem cells and ground tissue patterning. The Mediator subunit MED31 interacted with SCR but not SHR. Reduction of MED31 disrupted the spatiotemporal activation of CYCLIND6;1 (CYCD6;1), leading to defective asymmetrical division of stem cells generating ground tissue. MED31 was recruited to the promoter of CYCD6;1 in an SCR-dependent manner. MED31 was involved in the formation of a dynamic MED31/SCR/SHR ternary complex through the interface protein SCR. We demonstrate that the relative protein abundance of MED31 and SHR in different cell types regulates the dynamic formation of the ternary complex, which provides a tunable switch to strictly control the spatiotemporal transcriptional output. This study provides valuable clues to understand the mechanism by which master transcriptional regulators control organ patterning.