Korla fragrant pear (Pyrus sinkiangensis), valued for its unique flavor, suffers from freezing damage in its native Xinjiang. Previous studies indicated a strong correlation between low-temperature stress and the expression of LEA genes, particularly PsLEA4. This study cloned PsLEA4 from P. sinkiangensis and overexpressed it in paper mulberry (Broussonetia papyrifera). The encoded 368-amino-acid protein is localized to the endoplasmic reticulum. Under −4 °C stress, the proline and soluble protein contents in the overexpressing lines increased to 1.21-fold and 1.36-fold, respectively, compared to the wild type, while relative water content (RWC) reached 1.58-fold. And catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activities increased by 9%, 16%, and 38%, respectively. During overwintering, the transgenic line exhibited soluble protein content and RWC at 1.78-fold and 1.49-fold compared to those of the wild type, respectively. Malondialdehyde (MDA) and relative electrolyte leakage (REL) levels were only 66% and 63% of the wild type, while CAT and POD activities reached 1.87-fold, and SOD activity peaked at 2.49-fold. These adaptations were associated with improved cold tolerance and with bud break occurring 7–10 days earlier than in WT the following year. These findings could help to understand the molecular mechanisms of P. sinkiangensis for overwintering and provide new genetic resources to breed varieties of pear that can resist cold temperatures.

LEA_2 proteins are intrinsically disordered proteins implicated in plant abiotic stress tolerance; however, their functional characterization under salt and osmotic stress, particularly regarding stress-inducible peripheral redistribution, remains limited. SiLEA_2-6, an LEA_2 protein from the extreme-cold-tolerant species Saussurea involucrata, was identified from a cold-stress cDNA library, but its role in salt and osmotic tolerance remains unknown. In the present study, transgenic Arabidopsis thaliana Col-0 lines constitutively overexpressing SiLEA_2-6–eGFP were generated. Overexpression significantly enhanced salt and osmotic tolerance across germination, vegetative, and reproductive stages, as evidenced by improved germination rates, root elongation, survival, and physiological performance. Physiological analyses revealed improved membrane integrity (REL and MDA accumulation), enhanced osmotic adjustment, and preserved chlorophyll content. Subcellularly, SiLEA_2-6–eGFP displayed diffuse cytoplasmic distribution with intracellular punctate structures under non-stress conditions; within 60 min of salt or osmotic stress, it showed pronounced peripheral association, notably at guard cells and stomatal-adjacent regions. These findings demonstrate that SiLEA_2-6 enhances salt and osmotic tolerance in Arabidopsis, with stress-inducible peripheral enrichment consistent with a potential membrane-associated protective function. This study adds to the growing evidence that LEA_2 proteins confer tolerance not only to cold/freezing but also to salt and osmotic stress.

The following reference [1] has been retracted and removed from the original publication [1]:Liu, X

Low temperature is a major constraint limiting the productivity and distribution of crops, and aquaporins have emerged as important determinants of plant stress tolerance. Saussurea involucrata, an alpine plant adapted to extreme low-temperature environments, provides a valuable source of cold-tolerance genes, yet the contribution of its PIP1-type plasma membrane aquaporins to freezing and chilling tolerance in heterologous systems has not been established. Here, we isolated SiPIP1;5b, a PIP1-type plasma membrane intrinsic protein from S. involucrata, and constitutively overexpressed it in Arabidopsis thaliana and tomato (Solanum lycopersicum). Under freezing treatment (−4 °C, 4 h), SiPIP1;5b-overexpressing Arabidopsis lines showed markedly higher survival rates (72.0–81.5%) than the wild type (36.2%), together with lower relative electrolyte leakage and malondialdehyde (MDA) content and higher chlorophyll content. Under chilling stress (0 °C, 4 h), transgenic tomato plants likewise exhibited reduced electrolyte leakage and MDA accumulation, elevated activities of superoxide dismutase, catalase, and peroxidase, and increased proline content relative to wild-type plants. These results indicate that SiPIP1;5b enhances freezing and chilling tolerance and is associated with improved membrane stability, reduced accumulation of excessive reactive oxygen species, and enhanced antioxidant and osmoprotective responses. Our findings establish SiPIP1;5b as a promising candidate gene for improving low-temperature tolerance in crops.

Improving cotton yield without sacrificing fiber quality remains a major breeding challenge. In this study, a carpel-specific RNA interference construct targeting GhCKX3b was introduced into the elite upland cotton cultivar ‘Yuanmian 8’, which has high fiber quality but relatively low lint percentage. We evaluated the effects of this construct on cytokinin accumulation, yield-related traits, and fiber quality across T0, T1, and T2 generations. Carpel-specific suppression of GhCKX3b increased cytokinin content in T2 positive lines by 50.3% to 102.0% relative to wild-type. Transgenic lines consistently showed increased lint percentage, boll weight, and seeds per boll, while seed index decreased moderately. In the best-performing line, lint percentage increased from 36.4% to 45.8%, and boll weight from 6.30 g to 7.31 g. Multi-year field evaluations confirmed stable inheritance of these improvements across generations. Importantly, major fiber quality parameters—including length, strength, and micronaire—remained within high-quality cotton standards. These results indicate that carpel-specific GhCKX3b suppression effectively improves key yield components in a high-quality cotton background without compromising fiber quality. This study provides breeding-oriented evidence supporting the application of tissue-specific cytokinin regulation in cotton improvement.