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Low‐temperature storage is a widely used method for peach fruit storage. However, the impact of PpCBFs on pectin degradation during low‐temperature storage is unclear. As such, in this study, we stored the melting‐flesh peach cultivar "Fuli" at low temperature (LT, 6°C) and room temperature (RT, 25°C) to determine the effect of different temperatures on its physiological and biochemical changes. Low‐temperature storage can inhibit the softening of "Fuli" peaches by maintaining the stability of the cell wall. It was found that the contents of water‐soluble pectin and ionic‐soluble pectin in peach fruit stored at RT were higher than those stored at LT. The enzyme activities of polygalacturonase (PG), pectate lyase (PL), and pectin methylesterase (PME) were all inhibited by LT. The expressions of PpPME3, PpPL2, and PpPG were closely related to fruit firmness, but PpCBF2 and PpCBF3 showed higher expression levels at LT than RT. The promoters of PpPL2 and PpPG contain the DER motif, which suggested that PpCBF2 and PpCBF3 might negatively regulate their expression by directly binding to their promoters. These results indicated that LT may maintain firmness by activating PpCBFs to repress pectin‐degradation‐related enzyme genes during storage. [ABSTRACT FROM AUTHOR]

For a state estimation problem of nonlinear system, the square-root cubature Kalman filter (SCKF) is an effective method when the noise statistical characteristics are known. However, the performance of SCKF often degrade significantly in the face of uncertain noises interference, particularly in case of measurement or system failure. In this paper, we focus on improving the accuracy and robustness of SCKF under irregular noise. First, a weighted adaptive SCKF (WASCKF) algorithm is presented with moving window method. The WASCKF can improve the accuracy of SCKF by adaptively adjusting the covariances of measurement noise and process noise. Next, in order to further improve the robustness of WASCKF against the abrupt abnormal noise, a correction adaptive SCKF (CASCKF) algorithm based on fault detection mechanism is proposed. The CASCKF algorithm can detect whether there is a fault according to a statistical function of Chi-square distribution, and can judge and carry out the necessary correction processing by using an isolate rule. Finally, the performance of CASCKF is verified by numerical experiments of autonomous vehicle target tracking problem. The results show that the proposed CASCKF algorithm has good accuracy and robustness even with sudden abnormal noise interference. [ABSTRACT FROM AUTHOR]

The quantification and estimation of the driving style are crucial to improve the safety on the road and the acceptance of drivers with level2–level3(L2–L3) intelligent vehicles. Previous studies have focused on identifying the difference in driving style between categories, without further consideration of the driving behavior frequency, duration proportion properties, and the transition properties between driving style and behaviors. In this paper, a novel methodology to characterize the driving style is proposed by using the State–Action semantic plane based on the Bayesian nonparametric approach, i.e., hierarchical Dirichlet process–hidden semi–Markov model (HDP–HSMM). This method segments the time series driving data into fragment clusters with similar characteristics and construct the State–Action semantic plane based on the statistical characteristics of the state and action layer to label and interpret the fragment clusters. This intuitively and simply visualizes the driving performance of individual drivers, while the risk index of the individual drivers can also be obtained through semantic plane. In addition, according to the joint mutual information maximization (JIMI) approach, seven transition probabilities of driving behaviors are extracted from the semantic plane and applied to identify driving styles of drivers. We found that the aggressive drivers prefer high–risk driving behaviors, and the total duration and frequency of high–risk behaviors are greater than those of cautious and normal drivers. The transition probabilities among high–risk driving behaviors are also greater compared with low–risk behaviors. Moreover, the transition probabilities can provide rich information about driving styles and can improve the classification accuracy of driving styles effectively. Our study has practical significance for the regulation of driving behavior and improvement of road safety and the development of advanced driver assistance systems (ADAS). [ABSTRACT FROM AUTHOR]

Small heat shock proteins (sHSPs) are a group of chaperone proteins existed in all organisms. The functions of sHSPs in heat and abiotic stress responses in many glycophyte plants have been studied. However, their possible roles in halophyte plants are still largely known. In this work, a putative sHSP gene KvHSP26 was cloned from K. virginica. Bioinformatics analyses revealed that KvHSP26 encoded a chloroplastic protein with the typical features of sHSPs. Amino acid sequence alignment and phylogenetic analysis demonstrated that KvHSP26 shared 30%-77% homology with other sHSPs from Arabidopsis, cotton, durian, salvia, and soybean. Quantitative real-time PCR (qPCR) assays exhibited that KvHSP26 was constitutively expressed in different tissues such as leaves, stems, and roots, with a relatively higher expression in leaves. Furthermore, expression of KvHSP26 was strongly induced by salt, heat, osmotic stress, and ABA in K. virginica. All these results suggest that KvHSP26 encodes a new sHSP, which is involved in multiple abiotic stress responses in K. virginica, and it has a great potential to be used as a candidate gene for the breeding of plants with improved tolerances to various abiotic stresses. [ABSTRACT FROM AUTHOR]

The effects of increasing concentrations of lead (Pb) on malondialdehyde (MDA) content, soluble protein, Pb accumulation, nutrients, polyamines (PAs) and proline metabolism were investigated in sterilized seedlings of Potamogeton crispus L. after 5 d exposure. Significant oxidative stress was not caused, indicated by a little induction of MDA content and soluble proteins. Pb accumulation increased in a concentration-dependent manner and most of Pb was stored in the cell wall. Total P, Mg, Na and Zn rose and total Fe fell; total Ca increased at 25 μM Pb but then declined. The nutrients in cell wall fraction changed in the same pattern as total nutrients, whereas those in soluble and organelle fraction declined. Total putrescine (Put) decreased markedly, while total spermidine (Spd), spermine (Spm) and (Spd + Spm)/Put ratio increased progressively but then declined. The trends for free, perchloric acid soluble conjugated (PS-conjugated) and perchloric acid insoluble bound (PIS-bound) PAs were similar to those on total PAs, except that PIS-bound Spm increased significantly. Arginine decarboxylase (ADC) and ornithine decarboxylase (ODC) activities rose gradually, while diamine oxidase (DAO) initially increased but then declined. Proline content increased initially only to decline later, due to the increase of r -glutamyl kinase (GK) activity. Meanwhile, ornithine-d-aminotransferase (OAT) activity gradually reduced, while no significant change was observed in proline dehydrogenase (PDH) activity. Our results indicated that the tolerance of P . crispus to Pb stress was based on cell wall compartmentalization combined with increase of nutrients, alterations of PAs, and induction of proline. [ABSTRACT FROM AUTHOR]

The plastidic thioredoxin F-type (TrxF) protein plays an important role in plant carbohydrate metabolism and starch biosynthesis. In this work, a TrxF gene from maize, named ZmTrxF , was isolated and transformed into Arabidopsis . Constitutive expression of ZmTrxF significantly increased starch accumulation in transgenic plants. Real-time quantitative PCR (qRT-PCR) analyses showed that the transcript levels of starch biosynthetic genes, including those encoding sucrose synthase ( AtSUS ), phosphoglucomutase ( AtPGM ), ADP-glucose pyrophosphorylase ( AtAGPase-S1 , AtAGPase-S2 , AtAGPase-L1 and AtAGPase-L2 ), granule-bound starch synthase ( AtGBSS I and AtGBSS II ), soluble starch synthase ( AtSSS I , AtSSS II , AtSSS III and AtSSS IV ) and starch branching enzyme ( AtSBE I and AtSBE II ), were increased in transgenic plants. In contrast, there was no signifcant difference in the expression levels of α-amylase ( AtAMY3 ) and β-amylase ( AtBAM1 , AtBAM3 and AtBAM4 ) genes. Meanwhile, the activity of the major enzymes such as AGPase, GBSS, SSS and SBE involved in starch biosynthesis was higher in transgenic plants compared to that in the wild-type (WT). Furthermore, soluble sugar content was also increased in transgenic plants. All these results suggest that ZmTrxF could be used as a candidate gene for developing high starch-accumulating plants as alternative energy crops. [ABSTRACT FROM AUTHOR]

Manganese (Mn) toxicity in soil is a widely observed phenomenon, which seriously restricts growth, quality, and yield of various crops and fruits including apples. However, mechanisms underlying the regulation of polyamines (PAs) by brassinosteroids (BRs) to improve tolerance to Mn stress are still unclear. In this study, we investigated the effects of 2,4-epibrassinolide (EBL; a BR) on the expression of genes involved in BR signaling pathway, Mn accumulation, PAs-mediated responses (PA precursor levels, metabolic enzymes, and genes), and growth parameters in Mn-stressed Malus robusta Rehd. EBL application significantly modulated the expressions of genes related to BR signaling (MdBRI , MdBSK , etc.) and reduced Mn accumulation, along with improving the rate of increase in root length and plant height, relative water content, chlorophyll content, maximum photochemical efficiency of PSII (Fv/Fm), and actual photochemical efficiency (Φ PSII) and decreasing electrical conductivity. Furthermore, EBL application significantly reduced putrescine (Put) accumulation and increased spermine (Spm) content and (Spd + Spm)/Put ratio. EBL weakened ornithine (Orn) pathway, decreased ornithine decarboxylase (ODC) activity, and increased biosynthesis of Spm from Put via elevating the PA oxidase (PAO) activity and expression of MdSPDS , MdSPMS , and MdPAO. The trends for free, PS-conjugated, and PIS-bound PAs were similar to that of total PAs, except that no significant change was observed in free Spm, PS-conjugated Spd, and Spm, as well as PIS-bound Spd. This study revealed that BR-regulated PAs help in mitigating Mn toxicity and clarified the mechanisms of regulation of PAs by BRs in apple trees. • EBL application significantly activated the expressions of genes related to BR signaling. • Mn accumulation was significantly reduced after EBL application. • EBL application improved growth parameters and physiological indexes in M. robusta under Mn toxicity. • The strategy to overcome Mn stress was highly associated with the stimulation of PAs profile by BRs. • The mechanism of regulation of PAs by BRs against Mn stress was provided. [ABSTRACT FROM AUTHOR]

The growth and production of fruit trees are adversely affected by heavy metal pollution in orchard lands. Plant metal homeostasis and resistance are regulated by metal tolerance proteins (MTP), which function as divalent cation transporters. To understand the possible role of MTPs in fruit trees, we identified 20 MdMTPs in the apple genome. Phylogenetic and collinear relationship analyses revealed that they belonged to Zn-MTP, Fe/Zn-MTP and Mn-MTP subfamilies, and have gone through two tandem and six segmental duplication events under purifying selection. All MdMTPs were predicted to form homodimer, with each monocase containing a conserved cation efflux domain (CED), the typical structural feature of MTP family, and one or two HXXXD or DXXXD residues. Further spatiotemporal expression analyses indicated that all MdMTP genes were ubiquitously expressed, and most of them were induced by at least three heavy metal ions, in roots, stems or leaves. Yeast and Arabidopsis mutant complementation experiments verified the function of MdMTP11.1 in response to heavy metal stress. Our findings provide an important genetic foundation for the functional elucidation of MdMTP genes, which can be used as the potential gene candidates for the breeding of new fruit tree cultivars with improved tolerance to heavy metal stress. • A total number of 20 metal tolerance protein (MTP) genes were identified in apple. • All MdMTP proteins contained a cation efflux domain to work for metal ion efflux. • Tandem and segmental duplication events occurred in MdMTPs under purifying selection. • Most of MdMTPs were induced by at least three heavy metal ions in various organs. [ABSTRACT FROM AUTHOR]