Herbivore perception decreases photosynthetic carbon assimilation and reduces stomatal conductance by engaging 12‐oxo‐phytodienoic acid,mitogen‐activated protein kinase 4 and cytokinin perception

Herbivory‐induced changes in photosynthesis have been documented in many plant species; however, the complexity of photosynthetic regulation and analysis has thwarted progress in understanding the mechanism involved, particularly those elicited by herbivore‐specific elicitors. Here, we analysed the early photosynthetic gas exchange responses in Nicotiana attenuata plants after wounding and elicitation with Manduca sexta oral secretions and the pathways regulating these responses. Elicitation with M. sexta oral secretions rapidly decreased photosynthetic carbon assimilation (A_C) in treated and systemic (untreated, vascularly connected) leaves, which were associated with changes in stomatal conductance, rather than with changes in Rubisco activity and 1‐5 ribulose‐1,5‐bisphosphate turnover. Phytohormone profiling and gas exchange analysis of oral secretion‐elicited transgenic plants altered in phytohormone regulation, biosynthesis and perception, combined with micrografting techniques, revealed that the local photosynthetic responses were mediated by 12‐oxo‐phytodienoic acid, while the systemic responses involved interactions among jasmonates, cytokinins and abscisic acid signalling mediated by mitogen‐activated protein kinase 4. The analysis also revealed a role for cytokinins interacting with mitogen‐activated protein kinase 4 in CO₂‐mediated stomatal regulation. Hence, oral secretions, while eliciting jasmonic acid‐mediated defence responses, also elicit 12‐oxo‐phytodienoic acid‐mediated changes in stomatal conductance and A_C, an observation illustrating the complexity and economy of the signalling that regulates defence and carbon assimilation pathways in response to herbivore attack.     

中国两栖动物受威胁现状评估

为了了解我国两栖动物受威胁现状和致危因素, 进而制定相关的保护措施和开展国际合作, 本文依据中国两栖动物野生种群与生境现状, 利用《IUCN物种红色名录濒危等级和标准》(3.1版)和《IUCN物种红色名录标准在国家或地区的应用指南》(4.0版), 对中国已知的408种两栖动物的濒危状况进行了评估, 并编制了《中国两栖动物红色名录》。评估结果表明: 中国两栖动物有1种灭绝, 1种区域灭绝, 受威胁的两栖动物共计176种, 占评估物种总数的43.1%, 明显高于《IUCN濒危物种红色名录》(2015)的物种受威胁率(30.8%)。中国两栖动物特有种272种, 其中48.9%属于受威胁物种。中国两栖动物受威胁比例最高的目是有尾目(63.4%), 明显高于无尾目(39.0%); 受威胁比例最高的科是隐鳃鲵科(Cryptobranchidae) (仅有1种, 100%受威胁), 小鲵科(Hynobiidae) (86.7%)和叉舌蛙科(Dicroglossidae) (78.1%)。有11个省区的受威胁物种数占本省区两栖动物物种总数的30%及以上, 前3位分别是四川(40.8%)、广西(39.2%)和云南(37%)。中国大多数两栖动物物种分布在西南山地和华南地区, 以海拔2,000 m以下区域为主。栖息地退化或丧失、捕捉、环境污染列受威胁两栖动物致危因子的前3位。鉴于中国两栖动物区系的复杂性和独特性, 进一步加强两栖动物资源调查、种群和生境监测及相关科学研究, 仍是今后一段时期开展两栖动物多样性保护和濒危物种拯救行动的关键性基础工作。     

Face to Face

Over evolutionary time, humans have developed a selective sensitivity to features in the human face that convey information on sex, age, emotions, and intentions. This ability might not only be applied to our conspecifics nowadays, but also to other living objects (i.e., animals) and even to artificial structures, such as cars. To investigate this possibility, we asked people to report the characteristics, emotions, personality traits, and attitudes they attribute to car fronts, and we used geometric morphometrics (GM) and multivariate statistical methods to determine and visualize the corresponding shape information. Automotive features and proportions are found to covary with trait perception in a manner similar to that found with human faces. Emerging analogies are discussed. This study should have implications for both our understanding of our prehistoric psyche and its interrelation with the modern world.

Societal Risk Perception in Arab Countries: The Case of Kuwait

The study was aimed at examining data on risk perception from an Arab country—Kuwait—in order to support the existence of an Arab group as regards the way hazards are perceived. The data were gathered in 2003 and 2004 on two Kuwaiti samples of young adults and adolescents. The questionnaire used was the one used in studies conducted in Egypt and France. It comprised 141 items. The overall mean value observed in the Kuwaiti sample was close to the one found in the Egyptian sample. The linear association between Kuwaiti and French ratings was moderate (0.70) and of the same magnitude as the one found between Egyptian and French ratings. The association between Kuwaiti and Egyptian ratings was greater (0.90). In 80% of the hazards, the specific differences observed between the Kuwaiti and French ratings were the same as the ones observed between Egyptian and French ratings. The whole set of findings supports the hypothesis that Kuwaitis and Egyptians, despite huge differences in the socioeconomic environments in which they live, perceive societal risks in a common way, a way that is different from the way Western Europeans perceive them.     

The visual perceptual range of a lizard, <Emphasis Type="Italic">Tiliqua rugosa</Emphasis>

The fragmentation of landscapes produces habitat gaps where the distance between visual landmarks may exceed the perceptual range of a species and impose navigational constraints. We estimated the visual perceptual range of the Australian sleepy lizard, Tiliqua rugosa, by releasing individuals in the centre of a cleared arena in high temperature conditions, with a 0.5-m-high bush placed either 10, 20 or 30 m from the release site. Lizards were more likely to locate those bushes and shelter under them when they were closer, and no lizards found a bush at 30 m. In addition, lizards were less likely to move from the release point when bushes were at 30 m than when they were at the two closer distances. These data suggest that for sleepy lizards the perceptual range for a 0.5-m-high bush is about 20 m. In the uncleared chenopod shrub-land where these lizards live, suitable shelter bushes are an average of 10.5 m from any point in their home range, well within their perceptual range.     

Cytokinin activity of disubstituted aminopurines in Amaranthus

Cytokinin (CK) receptors have different affinities for certain ligands, and consequently, studies of the plant's response to CK analogues constitute a good approach to identify active compounds that trigger specific plant responses. In this study, N⁶ and N⁶,N⁶-substituted CK analogues were synthesized and their CK-like activity was examined in the Amaranthus betacyanin and the bacterial receptor assay. The compounds showed CK-like activities that were not always associated with their binding affinity to the Arabidopsis receptors AHK3 and CRE1/AHK4. The highest level of activity in both bioassays was obtained for the N⁶-alkylaminopurines, which showed an especially high binding affinity to AHK3. In contrast to previously published data, we found remarkable activity of N⁶,N⁶-alkylbenzylaminopurines in the Amaranthus betacyanin bioassay, which was not associated with their binding affinity to the tested receptors. The N⁶,N⁶-substituted CK that showed the highest activity at the lowest concentration, N⁶,N⁶-methylbenzylaminopurine (BAP-C1), was studied to determine its effect on different leaf parameters of whole Amaranthus plants, with benzylaminopurine (BAP) used as standard compound. The interaction with ethylene was examined in plants supplied with the ethylene-synthesis inhibitor aminooxiacetic acid (AOA). After 3 d, the CKs supplied in the solution culture exerted effects on leaf dry weight and gas-exchange parameters. These effects of exogenous CKs are suggested to be ethylene-synthesis dependent.     

Picking battles wisely: plant behaviour under competition

Plants are limited in their ability to choose their neighbours, but they are able to orchestrate a wide spectrum of rational competitive behaviours that increase their prospects to prevail under various ecological settings. Through the perception of neighbours, plants are able to anticipate probable competitive interactions and modify their competitive behaviours to maximize their long-term gains. Specifically, plants can minimize competitive encounters by avoiding their neighbours; maximize their competitive effects by aggressively confronting their neighbours; or tolerate the competitive effects of their neighbours. However, the adaptive values of these non-mutually exclusive options are expected to depend strongly on the plants' evolutionary background and to change dynamically according to their past development, and relative sizes and vigour. Additionally, the magnitude of competitive responsiveness is expected to be positively correlated with the reliability of the environmental information regarding the expected competitive interactions and the expected time left for further plastic modifications. Concurrent competition over external and internal resources and morphogenetic signals may enable some plants to increase their efficiency and external competitive performance by discriminately allocating limited resources to their more promising organs at the expense of failing or less successful organs.     

Population dynamics of Myzus persicae on tobacco in Yunnan Province,China, before and after augmentative releases of Aphidius gifuensis

The population dynamics of Myzus persicae were investigated in the field in a year without releases of Aphidius gifuensis (1998–1999), in a year with A. gifuensis releases (2000–2001) and several years later (2005–2007). The results showed that both high mean population densities and damage rates did not differ between 1998 and 1999, but were significantly lower in 2000–2001 and 2005–2007. Moreover, farmers also reported the decrease of M. persicae populations and attributed the declines to augmentative releases of A. gifuensis in their own fields, indicating farmers’ recognition in the effectiveness of A. gifuensis for M. persicae control. In addition, compared with the historical data on pesticide use for M. persicae control, the number of insecticide applications and cost of M. persicae control was sustained at a low level in 2007 (several years after release of A. gifuensis). This suggests that the augmentative releases of A. gifuensis could be effective and sustainable in M. persicae control.     

Enhanced perception in savant syndrome: patterns,structure and creativity

According to the enhanced perceptual functioning (EPF) model, autistic perception is characterized by: enhanced low-level operations; locally oriented processing as a default setting; greater activation of perceptual areas during a range of visuospatial, language, working memory or reasoning tasks; autonomy towards higher processes; and superior involvement in intelligence. EPF has been useful in accounting for autistic relative peaks of ability in the visual and auditory modalities. However, the role played by atypical perceptual mechanisms in the emergence and character of savant abilities remains underdeveloped. We now propose that enhanced detection of patterns, including similarity within and among patterns, is one of the mechanisms responsible for operations on human codes, a type of material with which savants show particular facility. This mechanism would favour an orientation towards material possessing the highest level of internal structure, through the implicit detection of within- and between-code isomorphisms. A second mechanism, related to but exceeding the existing concept of redintegration, involves completion, or filling-in, of missing information in memorized or perceived units or structures. In the context of autistics'' enhanced perception, the nature and extent of these two mechanisms, and their possible contribution to the creativity evident in savant performance, are explored.