The effect of high temperature on plant performance and survival is a topic of great interest given the ongoing rise in global heatwave frequency, duration, and intensity. The temperature at which photosystem II (PSII) is disrupted is often used as a proxy for photosynthetic heat tolerance. Our current understanding of PSII heat tolerance is predominantly shaped by ‘snapshot’ measurements that capture heat tolerance at a single point in time. However, growing evidence of dynamic thermal acclimation of PSII raises questions about the accuracy of current estimates of photosynthetic heat tolerance based on snapshot measurements. We believe that failing to account for acclimation may result in the underestimation of PSII heat tolerance and that the extent of acclimation can be predicted from leaf economic traits, leaf habit, plant water use strategies, photosynthetic pathway, and habitat. We also explore efforts to use spectroscopy techniques to predict acclimation, and the biotic and abiotic factors that may influence these predictions. Finally, we provide recommendations for the future incorporation of PSII heat tolerance and acclimation into models of the thermal limits of plant performance.

We are pleased to announce that Dr Alan Hough has been appointed as the new Editor-in-Chief of Research and Practice in Intellectual and Developmental Disabilities (RAPIDD). Dr Hough has been appointed for a three-year term, commencing officially on 1 October 2025. First published in 2014, RAPIDD is focused on practice in the support provided to people with intellectual disabilities. It is published twice a year.

Originally focused on corporate governance in the not-for-profit sector, Dr Hough has in recent years focused on quality and safety issues in disability service provision, with a particular emphasis on service provision to people with intellectual disabilities. Dr Hough has been a consultant to the Australian disability sector about these issues. He has been a regular contributor to RAPIDD. With Professor Christine Bigby AO, he co-edited Disability Practice: Safeguarding Quality Service Provision, and has served as Guest Co-Editor for the RAPIDD special issues on the Disability Royal Commission. Dr Hough holds the honorary appointment of Adjunct Professor of the Living with Disability Research Centre at La Trobe University, Australia.

Eye drop (ED) and vent brush (VB) application of live infectious laryngotracheitis virus (ILTV) vaccine provides protective immunity against disease, but little is known regarding the immune responses following application. This study compared the gene expression of immune markers associated with VB and ED ILTV vaccination in the conjunctiva, trachea and cloaca at 3, 5, 7 and 10 days post-vaccination (dpv) and 3, 5 and 7 days post-revaccination (dprv). The relative gene expression of markers associated with inflammatory responses and their regulation (CCL4, CCR5, IL2, IL4, IL6, IL17C, IFNG), pathogen recognition receptors (TLR2-2, TLR4, TLR7) and cell surface markers (CD4, CD8A, CD14, CD80) was evaluated by RT-PCR after ED or VB vaccination and revaccination using the alternate route [ED/VB (primary/booster), VB/ED). There was increased expression of inflammatory markers at vaccination sites following primary vaccination. In VB group, there was increased expression of IL6 and IFNG in cloaca (3 dpv) and IL2 in conjunctiva (7 dpv) compared to ED group (P < 0.05), while there was increased CCL4 expression in conjunctiva (5 dpv) in ED group compared to VB group. ED vaccination was associated with increased expression of IL2 and IL17C in trachea while VB vaccination was associated with increased expression of IL6 and IL17C in trachea. Similarly, ED/VB and VB/ED associated increases in IL2, IL6 and IL17C expression were observed in the revaccination sites. In conclusion, immune responses after the first and second ILTV vaccination were site-specific and associated with inflammatory responses in the mucosa of the vaccinated tissues and trachea.

This study evaluated the optimal energy-to-protein ratio in practical reduced-protein diets to evaluate the production performance, nutrient digestibility, and egg quality parameters of laying hens between 20 and 35 weeks of age. The best feed conversion ratio (FCR) of 2.548 was achieved at 15.5% crude protein (CP) and 100% recommended apparent metabolizable energy (AME) level with a reduced-protein diet, followed by 14% CP and 95% recommended AME levels (2.634) from 20 to 35 weeks of age (WOA) (p < 0.05). The yolk index was reduced only in diets containing 17% CP at 90% AME levels (p < 0.01) at week 35. Reduced dietary protein from 17% to 14% decreased egg weight and body weight gain between 20 and 35 WOA (p < 0.05) as well as decreased hen weight and shell breaking strength at 35 WOA (p < 0.05). However, it also reduced nitrogen excretion by 30% (p < 0.001) and increased protein digestibility by 17% (p < 0.01). Between 20 and 35 weeks of age, reducing dietary energy from 100% to 90% AME increased feed intake (p < 0.001), while excreta moisture, dry matter digestibility, and energy digestibility decreased at week 35 (p < 0.001). At week 27, reducing energy from 100% to 90% AME increased shell weight (p < 0.05), whereas lowering protein from 15.5% to 14% increased shell proportion (p < 0.05). Thus, it can be concluded that reducing dietary protein level from 17% to 15.5% with a 100% recommended AME level is optimal to improve feed efficiency while maintaining egg quality in laying hens from 20 to 35 WOA.