Nitrogen Supply Alters Rice Defense Against the Striped Stem Borer Chilo suppressalis.

Plant nutrition status is closely associated with plant defense against insect herbivores. However, the way nitrogen supply regulates rice anti-herbivore is not clear. This study investigated the effects of low (LN, 0.3 mM) and high (HN, 3 mM) nitrate levels on rice resistance against the striped stem borer Chilo suppressalis (SSB), one of the major destructive rice pests. Seven-day-old rice seedlings were cultured with different nitrate levels for 30 days and then inoculated with third instars of SSB. LN significantly enhanced rice anti-herbivore defense and lowered the total nitrogen content in the plants, but increased the content of free amino acids after SSB infestation. Additionally, LN significantly increased the accumulation of phenolic acids and flavonoids, especially lignin, resulting in enhanced constitutive defense in SSB-infested plants. SSB feeding led to a rapid accumulation of secondary metabolites. HN application led to the accumulation of metabolites derived from cinnamic acid, p-coumaric acid, p-coumaric CoA, feruloyl CoA, and apigenin, while LN led to the accumulation of metabolites derived from 3-dehydroquinic acid, phenylalanine, acetyl CoA, and aspartic acid. Collectively, our finding suggests that nitrogen deficiency enhances rice anti-herbivore defense via constitutive defense by the accumulation of phenolic acids and flavonoids.

Phosphoinositide 3-Kinase Promotes Oxidative Burst, Stomatal Closure and Plant Immunity in Bacterial Invasion.

Phosphoinositide 3-kinase (PI3K) plays a vital role in plant response to abiotic stress. However, the role of PI3K in plant immunity is largely unknown. This study showed that PI3K enhanced Arabidopsis resistance to Pseudomonas syringae pv tomato DC3000 (Pst DC3000) and Pst DC3000 (avrRpt2). Overexpression of AtVPS34 promoted stomatal closure while PI3K inhibitors blocked that after spray inoculation. Additionally, gene expression of AtVPS34 was increased upon infection by Pst DC3000 (avrRpt2), and SA upregulated AtVPS34 gene expression in this process. Furthermore, overexpression of AtVPS34 enhanced PR gene expression after syringe infiltration with Pst DC3000 (avrRpt2), while PI3K inhibitors inhibited that. The production of hydrogen peroxide and the expression of gene encoding antioxidant enzyme were both enhanced in AtVPS34 overexpressing lines after spray inoculation or syringe infiltration with Pst DC3000 (avrRpt2). Collectively, these results unraveled a novel and broad role of PI3K in plant immunity which promoted stomatal closure and PR gene expression possibly via regulating ROS production.

A robust anonymous biometric-based authenticated key agreement scheme for multi-server environments.

In order to improve the security in remote authentication systems, numerous biometric-based authentication schemes using smart cards have been proposed. Recently, Moon et al. presented an authentication scheme to remedy the flaws of Lu et al.'s scheme, and claimed that their improved protocol supports the required security properties. Unfortunately, we found that Moon et al.'s scheme still has weaknesses. In this paper, we show that Moon et al.'s scheme is vulnerable to insider attack, server spoofing attack, user impersonation attack and guessing attack. Furthermore, we propose a robust anonymous multi-server authentication scheme using public key encryption to remove the aforementioned problems. From the subsequent formal and informal security analysis, we demonstrate that our proposed scheme provides strong mutual authentication and satisfies the desirable security requirements. The functional and performance analysis shows that the improved scheme has the best secure functionality and is computational efficient.

Exponential Arithmetic Based Self-Healing Group Key Distribution Scheme with Backward Secrecy under the Resource-Constrained Wireless Networks.

In resource-constrained wireless networks, resources such as storage space and communication bandwidth are limited. To guarantee secure communication in resource-constrained wireless networks, group keys should be distributed to users. The self-healing group key distribution (SGKD) scheme is a promising cryptographic tool, which can be used to distribute and update the group key for the secure group communication over unreliable wireless networks. Among all known SGKD schemes, exponential arithmetic based SGKD (E-SGKD) schemes reduce the storage overhead to constant, thus is suitable for the the resource-constrained wireless networks. In this paper, we provide a new mechanism to achieve E-SGKD schemes with backward secrecy. We first propose a basic E-SGKD scheme based on a known polynomial-based SGKD, where it has optimal storage overhead while having no backward secrecy. To obtain the backward secrecy and reduce the communication overhead, we introduce a novel approach for message broadcasting and self-healing. Compared with other E-SGKD schemes, our new E-SGKD scheme has the optimal storage overhead, high communication efficiency and satisfactory security. The simulation results in Zigbee-based networks show that the proposed scheme is suitable for the resource-restrained wireless networks. Finally, we show the application of our proposed scheme.

Safety and tolerability of bismuthyl ecabet suspension, a novel anti-ulcer agent, following single and multiple oral dose administration in healthy Chinese subjects.

BACKGROUND: Bismuthyl ecabet is a combination of sulfodehydroabietic acid and bismuth, which forms a new type of salt that is useful in treating peptic ulcers and gastritis. OBJECTIVE: This study was designed to assess the safety and tolerability of bismuthyl ecabet suspension in healthy Chinese subjects. METHODS: For the study 77 volunteers were randomized into single- or multiple-dose groups for oral administration of bismuthyl ecabet 200-1600 mg once daily or 1200 mg twice daily for 7 days. Safety and tolerability were assessed by adverse events, physical examination and serum biochemistry. RESULTS: In both the single- and multiple-dose studies, no severe adverse events were observed in any of the volunteers. The main adverse events caused by the drug in single-dose groups were an increase in serum alanine transaminase (ALT), γ-glutamyl transpeptidase, blood urea nitrogen, total bilirubin and skin rash. The numbers of adverse events judged to be possibly related to the drug were 2/18 in the 400 mg, 2/18 in the 800 mg, 1/8 in the 1200 mg, and none in the 200 or 1600 mg dose groups. In the multiple-dose studies, an increased serum ALT and aspartate transaminase (AST) was found in one subject after 7 days of administration of the drug. All serum biochemistry returned to normal levels and skin rash resolved after 7 days without any special treatment. CONCLUSION: Bismuthyl ecabet was shown to be safe and well tolerated in healthy Chinese subjects. The oral dosing regimen selected for subsequent phase II/III clinical trials was 800 mg twice daily.