Background Plants are sessile organisms that have the ability to integrate external cues into metabolic and developmental signals. The cues initiate specific signal cascades that can enhance the tolerance of plants to stress, and these mechanisms are crucial to the survival and fitness of plants. The adaption of plants to stresses is a complex process that involves decoding stress inputs as energy-deficiency signals. The process functions through vast metabolic and/or transcriptional reprogramming to re-establish the cellular energy balance. Members of the mitochondrial energy dissipation pathway (MEDP), alternative oxidases (AOXs) and uncoupling proteins (UCPs), act as energy mediators and might play crucial roles in the adaption of plants to stresses. However, their roles in plant growth and development have been relatively less explored. Scope This review summarizes current knowledge about the role of members of the MEDP in plant development as well as recent advances in identifying molecular components that regulate the expression of AOXs and UCPs. Highlighted in particular is a comparative analysis of the expression, regulation and stress responses between AOXs and UCPs when plants are exposed to stresses, and a possible signal cross-talk that orchestrates the MEDP, reactive oxygen species (ROS), calcium signalling and hormone signalling. Conclusions The MEDP might act as a cellular energy/metabolic mediator that integrates ROS signalling, energy signalling and hormone signalling with plant development and stress accumulation. However, the regulation of MEDP members is complex and occurs at transcriptional, translational, post-translational and metabolic levels. How this regulation is linked to actual fluxes through the AOX/UCP in vivo remains elusive.

Abies pindrow is a keystone tree species of temperate forests in the Himalayan range with immense ecological significance. The current study was designed to investigate the spatial distribution, population structure, associated flora, and sustainability of Abies pindrow in the temperate forests of Azad Jammu and Kashmir (AJK), Pakistan. Vegetation data were collected from 48 forest sites distributed in six districts of AJK with respect to the geography, microclimates, and vegetation structure by employing a systematic quadrate-based methodology. Abies pindrow populations were characterized by an average stem density of 183.9 trees/ha with an average basal area cover of 789 cm. A. pindrow populations showed a regeneration value of 555.6 seedlings/ha. A digital elevation model revealed that A. pindrow exhibited a large extent of distribution in an altitudinal range of 1800–3400 m. GIS analysis identified that north-facing slopes with a moderate degree of slope steepness constitutes the preferred habitat of the species in the Kashmir mountains. A floristic analysis revealed that a total of 282 species from 74 plant families comprised the associated flora of A. pindrow-dominated forests with Pinus wallichiana, Picea smithiana, Aesculus indica, and Viburnum grandiflorum as codominant companion species. A. pindrow forests exhibited significant levels of species diversity and richness with average values of Simpson’s diversity as 0.94, Shannon’s diversity as 3.09, species richness as 1.45, and maturity index value as 45.9%. The A. pindrow populations in the study area were found to be subjected to significant deforestation pressure along with overgrazing and erosion impacts. Results provide valuable scientific information for the conservation management of A. pindrow populations, ensuring the sustainability of temperate forest ecosystems in the Western Himalayan region of Kashmir.

Phaseolus vulgaris L. is the major pulse cultivated and culturally inculcated in the food habits of the locals in the Himalayan mountainous region of Azad Jammu and Kashmir (AJK), Pakistan. The current study was designed to investigate the role of P. vulgaris cultivation in providing livelihood support and to evaluate its production and consumption patterns correlated with the household variables in the state of AJK. The socio-economic data was collected from nine bean cultivated areas in six districts of AJK. The data was acquired by administrating a total of 522 detailed semi structured questionnaires from a diverse array of the respondents following the snowball technique focusing on yield, consumption, revenue generation and livelihood support provided by bean cultivation. The results revealed that common bean cultivation provided significant livelihood support to the local mountainous populations with an average annual income of 50.80 $/family. Subsequently, bean production contributed an average annual per capita income of 6.81 $ in the area, which was attributed to the large family size. Local populations showed an average bean production of 33.93 kg/family, whereas the average annual bean consumption was recorded as 31.99 kg/family in the region. Bean crops were recorded to have an average price of $1.49/kg, with significant variations in the study area correlated with local yield. A data analysis indicated a strong correlation in bean production and consumption patterns. Common bean farmers had a very small farm size, averaging 0.24 ha, where 100% of farmers cultivated common beans as an intercrop with Maize as the primary crop. A Pearson’s test (p value < 0.05) revealed significant correlations between land holding and bean production as well as consumption, and bean production with annual per capita income. Small farm size, declining soil fertility, low bean pricing and the unavailability of market mechanisms were identified as the major challenges faced by the common bean farmers. It is recommended to employ an integrated bean farming approach to enhance the economic impact of common bean cultivation in the socioeconomic appraisal of the local populations.

Soil salinity significantly represses plant development and growth. Mechanisms involved sodium (Na⁺) extrusion and compartmentation, intracellular membrane trafficking as well as redox homeostasis regulation play important roles in plant salt tolerance. In this study, we report that Patellin1 (PATL1), a membrane trafficking-related protein, modulates salt tolerance in Arabidopsis. The T-DNA insertion mutant of PATL1 (patl1) with elevated PATL1 transcription level displays salt-sensitive phenotype. PATL1 partially associates with plasma membrane (PM) and endosomal system, and might participate in regulating membrane trafficking. Interestingly, PATL1 interacts with SOS1, a PM Na⁺/H⁺ antiporter in Salt-Overly-Sensitive (SOS) pathway, and the PM Na⁺/H⁺ antiport activity is lower in patl1 than that in Col-0. Furthermore, reactive oxygen species (ROS) content is higher in patl1 and the antioxidants redox signaling is partially disrupted in patl1 under salt stress condition. Artificially elimination of ROS could partially rescue the salt-sensitive phenotype of patl1. Taken together, our results indicate that PATL1 participates in plant salt tolerance by regulating Na⁺ transport at least in part via SOS1, and by modulating cellular redox homeostasis during salt stress.

Transcription factor ABSCISIC ACID INSENSITIVE3 (ABI3) is known to play a major role in regulating seed dormancy, germination, seedling development as well as stress responses. ABI3 is conserved among land plants; however, its roles in non-seed plants under stress conditions have not been well characterized. In this study, we report that ABI3 is involved in freezing tolerance regulation during cold acclimation at least in part through ABA signaling pathway in moss Physcomitrella patens (P. patens). Deletion of PpABI3 (abi3-1) compromises the induction of genes related to cold response and antioxidative protection, resulting in reduced accumulation of cryoprotectants and antioxidants. In addition, photosystem II (PSII) activity is repressed in abi3-1 during cold acclimation partially due to alternations of photosynthetic protein complexes compositions. The gametophyteofabi3-1 displays severe growth inhibition and developmental deficiency under low temperature condition, while two independent complementary lines display phenotypes similar to that of wild-type P. patens (WT). Furthermore, the freezing tolerance of abi3-1 was significantly affected by deletion of PpABI3. These data revealed that PpABI3 plays an important role in low temperature response and freezing tolerance in P. patens.