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In Arabidopsis thaliana, female gametophyte (FG) development is accompanied by the formation and expansion of the large vacuole in the FG; this is essential for FG expansion, nuclear polar localization, and cell fate determination. Arabidopsis VACUOLELESS GAMETOPHYTES (VLG) facilitates vesicular fusion to form large vacuole in the FG, but the regulation of VLG remains largely unknown. Here, we found that gain-of-function mutation of BRASSINOSTEROID INSENSITIVE2 (BIN2) (bin2-1) increases VLG abundance to induce the vacuole formation at stage FG1, and leads to abortion of FG. Loss-of-function mutation of BIN2 and its homologs (bin2-3 bil1 bil2) reduced VLG abundance and mimicked vlg/VLG phenotypes. Knocking down VLG in bin2-1 decreased the ratio of aberrant vacuole formation at stage FG1, whereas FG1-specific overexpression of VLG mimicked the bin2-1 phenotype. VLG partially rescued the bin2-3 bil1 bil2 phenotype, demonstrating that VLG acts downstream of BIN2. Mutation of VLG residues that are phosphorylated by BIN2 altered VLG stability and a phosphorylation mimic of VLG causes similar defects as did bin2-1. Therefore, BIN2 may function by interacting with and phosphorylating VLG in the FG to enhance its stability and abundance, thus facilitating vacuole formation. Our findings provide mechanistic insight into how the BIN2-VLG module regulates the spatiotemporal formation of the large vacuole in FG development.

Macroautophagy/autophagy is a finely-regulated process in which cytoplasm encapsulated within transient organelles termed autophagosomes is delivered to lysosomes or vacuoles for degradation. Phospholipids, particularly phosphatidic acid (PA) that functions as a second messenger, play crucial and differential roles in autophagosome formation; however, the underlying mechanism remains largely unknown. Here we demonstrated that PA inhibits autophagy through competitive inhibition of the formation of ATG3 (autophagy-related)-ATG8e and ATG6-VPS34 (vacuolar protein sorting 34) complexes. PA bound to GAPC (glyceraldehyde-3-phosphate dehydrogenase) or PGK (phosphoglycerate kinase) and promoted their interaction with ATG3 or ATG6, which further attenuated the interactions of ATG3-ATG8e or ATG6-VPS34, respectively. Structural and mutational analyses revealed the mechanism of PA binding with GAPCs and PGK3, and that GAPCs or ATG8e competitively interacted with ATG3, and PGK3 or VPS34 competitively interacted with ATG6, at the same binding interface. These results elucidate the molecular mechanism of how PA inhibits autophagy through binding GAPC or PGK3 proteins and expand the understanding of the functional mode of PA, demonstrating the importance of phospholipids in plant autophagy and providing a new perspective for autophagy regulation by phospholipids.

Ovule initiation is a key step that strongly influences ovule number and seed yield. Notably, mutants with enhanced brassinosteroid (BR) and cytokinin (CK) signaling produce more ovules and have a higher seed number per silique (SNS) than wild-type plants. Here, we crossed BR- and CK-related mutants to test whether these phytohormones function together in ovule initiation. We determined that simultaneously enhancing BR and CK contents led to higher ovule and seed numbers than enhancing BR or CK separately, and BR and CK enhanced each other. Further, the BR-response transcription factor BZR1 directly interacted with the CK-response transcription factor ARABIDOPSIS RESPONSE REGULATOR1 (ARR1). Treatments with BR or BR plus CK strengthened this interaction and subsequent ARR1 targeting and induction of downstream genes to promote ovule initiation. Enhanced CK signaling partially rescued the reduced SNS phenotype of BR-deficient/insensitive mutants whereas enhanced BR signaling failed to rescue the low SNS of CK-deficient mutants, suggesting that BR regulates ovule initiation and SNS through CK-mediated and CK-independent pathways. Our study thus reveals that interaction between BR and CK promotes ovule initiation and increases seed number, providing important clues for increasing the seed yield of dicot crops. This article is protected by copyright. All rights reserved.

Seed is the offspring of angiosperms. Plants produce large numbers of seeds to ensure effective reproduction and survival in varying environments. Ovule is a fundamentally important organ and is the precursor of the seed. In Arabidopsis and other plants characterized by multi-ovulate ovaries, ovule initiation determines the maximal ovule number, thus greatly affecting seed number per fruit and seed yield. Investigating the regulatory mechanism of ovule initiation has both scientific and economic significance. However, the genetic and molecular basis underlying ovule initiation remains unclear due to technological limitations. Very recently, rules governing the multiple ovules initiation from one placenta have been identified, the individual functions and crosstalk of phytohormones in regulating ovule initiation have been further characterized, and new regulators of ovule boundary are reported, therefore expanding the understanding of this field. In this review, we present an overview of current knowledge in ovule initiation and summarize the significance of ovule initiation in regulating the number of plant offspring, as well as raise insights for the future study in this field that provide potential routes for the improvement of crop yield.

Vacuoles are organelles in plant cells that play pivotal roles in growth and developmental regulation. The main functions of vacuoles include maintaining cell acidity and turgor pressure, regulating the storage and transport of substances, controlling the transport and localization of key proteins through the endocytic and lysosomal-vacuolar transport pathways, and responding to biotic and abiotic stresses. Further, proteins localized either in the tonoplast (vacuolar membrane) or inside the vacuole lumen are critical for fruit quality. In this review, we summarize and discuss some of the emerging functions and regulatory mechanisms associated with plant vacuoles, including vacuole biogenesis, vacuole functions in plant growth and development, fruit quality, and plant-microbe interaction, as well as some innovative research technology that has driven advances in the field. Together, the functions of plant vacuoles are important for plant growth and fruit quality. The investigation of vacuole functions in plants is of great scientific significance and has potential applications in agriculture.

Two types of tonoplast proton pumps, H+ -pyrophosphatase (V-PPase) and the H+ -ATPase (V-ATPase), establish the proton gradient that powers molecular traffic across the tonoplast thereby facilitating turgor regulation and nutrient homeostasis. However, how proton pumps regulate development remains unclear. In this study, we investigated the function of two types of proton pumps in Arabidopsis embryo development and pattern formation. While disruption of either V-PPase or V-ATPase had no obvious effect on plant embryo development, knocking out both resulted in severe defects in embryo pattern formation from the early stage. While the first division in wild-type zygote was asymmetrical, a nearly symmetrical division occurred in the mutant, followed by abnormal pattern formation at all stages of embryo development. The embryonic defects were accompanied by dramatic differences in vacuole morphology and distribution, as well as disturbed localisation of PIN1. The development of mutant cotyledons and root, and the auxin response of mutant seedlings supported the hypothesis that mutants lacking tonoplast proton pumps were defective in auxin transport and distribution. Taking together, we proposed that two tonoplast proton pumps are required for vacuole morphology and PIN1 localisation, thereby controlling vacuole and auxin-related developmental processes in Arabidopsis embryos and seedlings.

Plant ovule initiation determines the maximum of ovule number and has a great impact on the seed number per fruit. The detailed processes of ovule initiation have not been accurately described, although two connected processes, gynoecium and ovule development, have been investigated. Here, we report that ovules initiate asynchronously. The first group of ovule primordia grows out, the placenta elongates, the boundaries of existing ovules enlarge and a new group of primordia initiates from the boundaries. The expression pattern of different marker genes during ovule development illustrates that this asynchronicity continues throughout whole ovule development. PIN-FORMED1 polar distribution and auxin response maxima correlate with ovule primordia asynchronous initiation. We have established computational modeling to show how auxin dynamics influence ovule primordia initiation. Brassinosteroid signaling positively regulates ovule number by promoting placentae size and ovule primordia initiation through strengthening auxin response. Transcriptomic analysis demonstrates numerous known regulators of ovule development and hormone signaling, and many new genes are identified that are involved in ovule development. Taken together, our results illustrate that the ovule primordia initiate asynchronously and the hormone signals are involved in the asynchrony., Summary: Ovule primordia initiation, which determines the maximum ovule number and subsequent seed number in Arabidopsis, is asynchronous and is regulated by PIN1 polar distribution and the auxin response.

The main determinant of crop yield is seed yield. In Arabidopsi, many of the genes that regulate seed number are involved in gametophyte and zygote development, and their overexpression cannot increase seed number. However, several mutants with enhanced brassinosteroid (BR) and cytokinin (CK) signals show increased seed number per silique (SNS). Here, we studied the crosstalk between BR and CK signals in regulating SNS through crossing BR- and CK-related mutants. Compared with the mutants ckx3 ckx5 and bzr1-1D , the triple mutant ckx3 ckx5 bzr1-1D with enhanced BR and CK signals formed elongated placentae and showed increased ovule initiation and SNS, indicating that BR and CK synergistically up-regulate SNS. Although BR enhanced the CK signal and CK enhanced the BR signal, while CK partially rescued the phenotypes of BR deficient- and -insensitive mutants, BR could not rescue the phenotypes of CK-deficient mutants. This suggested that CK functions downstream of BR in regulating SNS and that BR regulates SNS through CK-mediated or CK-independent pathways. Comparative transcriptome analyses of ckx3 ckx5 , bzr1-1D , and ckx3 ckx5 bzr1-1D identified known and new genes involved in ovule initiation. The BR-induced transcription factor BZR1 was found to directly interact with the B-type regulator of CK, ARR1, and this interaction enhanced the ability of ARR1 to target and induce genes related to ovule development. Our results demonstrate that BR and CK synergistically increase SNS through co-regulating downstream genes involved in ovule identity and initiation. The genes involved in this process have potential applications in enhancing crop yield.

Three antistatic additives were applied to improve the antistatic abilities of lead styphnate and lead azide. It has been found that PVA and DEX are more effective antistatic additives for LA, whereas CMC and DEX are more appropriate for LS by electrostatic accumulation test. The dynamic vacuum stability test (DVST) method was used to investigate the thermal decomposition of LA/PVA, LA/DEX, LS/CMC, LS/DEX, thermal kinetic parameters are obtained. The results show that antistatic additives have influence on the thermal kinetic parameters that lead to the thermal decomposition reaction which requires more energy, thus increasing the thermal stability of primary explosive. However, the reaction mechanism function that insure the explosive properties remained unchanged.

Sediment layer can change the dynamic property of reservoir water. As a result, the dynamic response of dam body would be affected. In this paper, the sediment layer is simulated as saturated liquid-solid two-phase media, and the finite element model of gravity dam-reservoir water-sediment system is established with the gradual enlargement mesh method. Then the influence of sediment layer on seismic wave motion is studied with this model. The calculation result shows that the energy radiation of far field of foundation, reservoir water and sediment can be considered efficiently in this model, and with the thickening of sediment layer the dynamic water pressure on dam face decreases.

The thermal kinetic performance and storage life of tris(carbohydrazide)manganese(II) perchlorate (GTM), tris(carbohydrazide)nickel(II) perchlorate (GTN), tris(carbohydrazide)zinc(II) perchlorate (GTX), and tris(carbohydrazide)cadmium(II) perchlorate (GTG), as important high-energy and green materials, were carried out by the DSC, (thermogravimetric) TG, and a dynamic pressure measuring thermal analysis (DPTA) method. The thermal behavior, kinetics, thermal safety, and storage life of them were investigated. The results show that there are three mass-loss stages in TG curves, and one endothermic peak and two exothermic peaks in DSC curve for them. The first mass-loss stages are the melting processes, and the thermal decompositions have happened in this stage. The kinetic data were obtained from the DSC and TG curves by integral and differential methods. The most probable kinetic models and kinetic equations were suggested by polynomial fitting the kinetic data. The specific heat capacity was determined with theoretical calculation method, and then self-accelerating decomposition temperature (TSADT), thermal ignition temperature (TTIT), critical temperatures of thermal explosion (Tb), and the adiabatic time-to-explosion (tTIAD) are calculated, respectively. The storage lives of 0.01 % conversion rate for GTM, GTN, GTX, and GTG at 25 °C are 4.52a (annual), 9.26a 10.75a, and 7.57a. GTX is the most excellent carbohydrazide perchlorate.

Binocular stereo vision is a common passive ranging method, which directly simulates the approach of human visual. It can flexibly measure the stereo information in a complex condition. However there is a problem that binocular vision ranging accuracy is not high , one of the reasons is the low precision of the stereo image pairs matching . In this paper, based on trinocular vision imaging ranging algorithm of constraint matching, we use trinocular visual ranging system which is composed of three parallel placed cameras to image and achieve distance measurement of the target. we use calibration method of Zhang to calibrate the cameras, firstly, the three cameras are calibrated respectively, then using the results to get three groups binocular calibration. Thereby the relative position information of each camera are obtained. The using of the information obtained by the third camera can reduce ambiguity of corresponding points matching in a Binocular camera system. limiting search space by the epipolar constraint and improve the matching speed, filtering the distance information , eliminate interference information which brings by the feature points on the prospect and background to obtain a more accurate distance result of target. Experimental results show that, this method can overcome the limitations of binocular vision ranging , effectively improving the range accuracy.