Reduced CO\u3csub\u3e2\u3c/sub\u3e/O\u3csub\u3e2\u3c/sub\u3e specificity of ribulose-bisphosphate carboxylase/oxygenase in a temperature-sensitive chloroplast mutant of \u3ci\u3eChlamydomonas\u3c/i\u3e

The Chlamydomonas reinhardtii chloroplast mutant 68-4PP is phenotypically indistinguishable from wild type at 25°C but fails to grow photosynthetically at 35°C. It had about 30% of the wild-type level of ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39) holoenzyme and carboxylase activity when grown at 25°C, but less than 15% when grown at 35°C. Pulse-labeling with 35S showed that the decrease in enzyme level at the restrictive temperature was not a result of reduced synthesis of enzyme subunits. The CO2/O2 specificity factor (VcKo/VoKc, where Vc and Vo are Vmax values for carboxylation and oxygenation and Kc and Ko are Km values for CO2 and 02) of the mutant enzyme was found to be significantly less than that of the wild-type enzyme (54 ± 2 and 62 ± 1, respectively), and this alteration was accompanied by increases in Ko and Kc and a decrease in Vc/Vo. DNA sequencing revealed a single missense mutation in the 684PP chloroplast large-subunit gene. This mutation causes leucine to be replaced by phenylalanine at position 290 in the large subunit polypeptide sequence. These results (i) support previous studies that implicated this region of the large subunit as an important structural component of the enzyme\u27s function and (ii) demonstrate that chloroplast genetic modification of the CO2/O2 specificity factor of a plant-type carboxylase/oxygenase is feasible

Reduced CO\u3csub\u3e2\u3c/sub\u3e/O\u3csub\u3e2\u3c/sub\u3e specificity of ribulose-bisphosphate carboxylase/oxygenase in a temperature-sensitive chloroplast mutant of \u3ci\u3eChlamydomonas\u3c/i\u3e

The Chlamydomonas reinhardtii chloroplast mutant 68-4PP is phenotypically indistinguishable from wild type at 25°C but fails to grow photosynthetically at 35°C. It had about 30% of the wild-type level of ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39) holoenzyme and carboxylase activity when grown at 25°C, but less than 15% when grown at 35°C. Pulse-labeling with 35S showed that the decrease in enzyme level at the restrictive temperature was not a result of reduced synthesis of enzyme subunits. The CO2/O2 specificity factor (VcKo/VoKc, where Vc and Vo are Vmax values for carboxylation and oxygenation and Kc and Ko are Km values for CO2 and 02) of the mutant enzyme was found to be significantly less than that of the wild-type enzyme (54 ± 2 and 62 ± 1, respectively), and this alteration was accompanied by increases in Ko and Kc and a decrease in Vc/Vo. DNA sequencing revealed a single missense mutation in the 684PP chloroplast large-subunit gene. This mutation causes leucine to be replaced by phenylalanine at position 290 in the large subunit polypeptide sequence. These results (i) support previous studies that implicated this region of the large subunit as an important structural component of the enzyme\u27s function and (ii) demonstrate that chloroplast genetic modification of the CO2/O2 specificity factor of a plant-type carboxylase/oxygenase is feasible

Human resource management–well‐being–performance research revisited:Past, present, and future

The authors provide an up‐to‐date theoretically based qualitative review of research dealing with the relationship between HRM, employee well‐being, and individual/organisational performance (HRM‐WB‐IOP research). The review is based on a systematic critical analysis of all HRM‐WB‐IOP studies (N = 46) published in 13 core HRM and management journals in the 2000 to 2018 period. The authors first identify different theoretical models of the HRM‐WB‐IOP relationship, which they then use to map research in the area. The results show that mutual gains conceptualisations play a dominant role in extant HRM‐WB‐IOP research, at the expense of alternative conflicting outcomes and mutual losses models, which are also shown to receive very limited empirical support across the 46 studies. As part of this mapping exercise, the authors identify important knowledge gaps in the area and conclude by setting out a number of key recommendations for future research to address these gaps

Willing and able: action-state orientation and the relation between procedural justice and employee cooperation

Existing justice theory explains why fair procedures motivate employees to adopt cooperative goals, but it fails to explain how employees strive towards these goals. We study self-regulatory abilities that underlie goal striving; abilities that should thus affect employees’ display of cooperative behavior in response to procedural justice. Building on action control theory, we argue that employees who display effective self-regulatory strategies (action oriented employees) display relatively strong cooperative behavioral responses to fair procedures. A multisource field study and a laboratory experiment support this prediction. A subsequent experiment addresses the process underlying this effect by explicitly showing that action orientation facilitates attainment of the cooperative goals that people adopt in response to fair procedures, thus facilitating the display of actual cooperative behavior. This goal striving approach better integrates research on the relationship between procedural justice and employee cooperation in the self-regulation and the work motivation literature. It also offers organizations a new perspective on making procedural justice effective in stimulating employee cooperation by suggesting factors that help employees reach their adopted goals

The Importance of Being Psychologically Empowered: Buffering the Negative Effects of Employee Perceptions of Leader-Member Exchange Differentiation

Although differentiated relationships among leaders and their followers are fundamental to Leader-Member Exchange (LMX) theory, research provides limited knowledge about whether employees’ responses to individual perceptions of LMX differentiation are uniform. In a field study, we examined whether individual-level psychological empowerment buffers the negative relationship between perceived LMX differentiation and job satisfaction, and found that the negative relationship is strongest under low employee psychological empowerment conditions, as compared to high psychological empowerment. Furthermore, in a multi-wave field study and an experiment, we extended these initial findings by investigating employees’ perceptions of supervisory fairness as a mediator of this moderated relationship. We found that the indirect effect between perceived LMX differentiation and job satisfaction, through supervisory fairness perceptions, is strongest under low employee psychological empowerment, as compared to high psychological empowerment. Collectively, our findings showcase the importance of psychological empowerment as a tool for employees to use to counteract the negative effect of perceived differentiated contexts

The motivational antecedents of the development of mental toughness: a self-determination theory perspective

Mental toughness is a topic that has received growing attention in psychological literature over the past decade. Although some researchers have attempted to understand how mental toughness is developed, little effort has been made to integrate an understanding of mental toughness development with established psychological theory and research. The aim of our review is to demonstrate the utility of theory and research on motivation for understanding mental toughness and its development. In particular, we propose that self-determination theory provides a sound basis for understanding the motivational antecedents of mental toughness. To achieve our aim, we consider concepts that bridge mental toughness and self-determination theory literature, namely striving, surviving, and thriving. We conclude our review with suggestions for future lines of empirical enquiry that could be pursued to further test our propositions