The Cell Wall Proteome of Craterostigma plantagineum Cell Cultures Habituated to Dichlobenil and Isoxaben

Specific metabolic and cellular mechanisms of the vegetative desiccation tolerance in resurrection plants for adaptation to extreme dryness

MAIN CONCLUSION

Substantial advancements have been made in our comprehension of vegetative desiccation tolerance in resurrection plants, and further research is still warranted to elucidate the mechanisms governing distinct cellular adaptations. Resurrection plants are commonly referred to as a small group of extremophile vascular plants that exhibit vegetative desiccation tolerance (VDT), meaning that their vegetative tissues can survive extreme drought stress (> 90% water loss) and subsequently recover rapidly upon rehydration. In contrast to most vascular plants, which typically employ water-saving strategies to resist partial water loss and optimize water absorption and utilization to a limited extent under moderate drought stress, ultimately succumbing to cell death when confronted with severe and extreme drought conditions, resurrection plants have evolved unique mechanisms of VDT, enabling them to maintain viability even in the absence of water for extended periods, permitting them to rejuvenate without harm upon water contact. Understanding the mechanisms associated with VDT in resurrection plants holds the promise of expanding our understanding of how plants adapt to exceedingly arid environments, a phenomenon increasingly prevalent due to global warming. This review offers an updated and comprehensive overview of recent advances in VDT within resurrection plants, with particular emphasis on elucidating the metabolic and cellular adaptations during desiccation, including the intricate processes of cell wall folding and the prevention of cell death. Furthermore, this review highlights existing unanswered questions in the field, suggests potential avenues for further research to gain deeper insights into the remarkable VDT adaptations observed in resurrection plants, and highlights the potential application of VDT-derived techniques in crop breeding to enhance tolerance to extreme drought stress.

Characterization of MdMYB68, a suberin master regulator in russeted apples

INTRODUCTION

Apple russeting is mainly due to the accumulation of suberin in the cell wall in response to defects and damages in the cuticle layer. Over the last decades, massive efforts have been done to better understand the complex interplay between pathways involved in the suberization process in model plants. However, the regulation mechanisms which orchestrate this complex process are still under investigation. Our previous studies highlighted a number of transcription factor candidates from the Myeloblastosis (MYB) transcription factor family which might regulate suberization in russeted or suberized apple fruit skin. Among these, we identified MdMYB68, which was co-expressed with number of well-known key suberin biosynthesis genes.

METHOD

To validate the MdMYB68 function, we conducted an heterologous transient expression in Nicotiana benthamiana combined with whole gene expression profiling analysis (RNA-Seq), quantification of lipids and cell wall monosaccharides, and microscopy.

RESULTS

MdMYB68 overexpression is able to trigger the expression of the whole suberin biosynthesis pathway. The lipid content analysis confirmed that MdMYB68 regulates the deposition of suberin in cell walls. Furthermore, we also investigated the alteration of the non-lipid cell wall components and showed that MdMYB68 triggers a massive modification of hemicelluloses and pectins. These results were finally supported by the microscopy.

DISCUSSION

Once again, we demonstrated that the heterologous transient expression in N. benthamiana coupled with RNA-seq is a powerful and efficient tool to investigate the function of suberin related transcription factors. Here, we suggest MdMYB68 as a new regulator of the aliphatic and aromatic suberin deposition in apple fruit, and further describe, for the first time, rearrangements occurring in the carbohydrate cell wall matrix, preparing this suberin deposition.

A molecular study of Italian ryegrass grown on Martian regolith simulant

In the last decade, the exploration of deep space has become the objective of the national space programs of many countries. The International Space Exploration Coordination Group has set a roadmap whose long-range strategy envisions the expansion of human presence in the solar system to progress with exploration and knowledge and to accelerate innovation. Crewed missions to Mars could be envisaged by 2040. In this scenario, finding ways to use the local resources for the provision of food, construction materials, propellants, pharmaceuticals is needed. Plants are important resources for deep space manned missions because they produce phytochemicals of pharmaceutical relevance, are sources of food and provide oxygen which is crucial in bioregenerative life support systems. Growth analysis and plant biomass yield have been previously evaluated on Martian regolith simulants; however, molecular approaches employing gene expression analysis and proteomics are still missing. The present work aims at filling this gap by providing molecular data on a representative member of the Poaceae, Lolium multiflorum Lam., grown on potting soil and a Martian regolith simulant (MMS-1). The molecular data were complemented with optical microscopy of root/leaf tissues and physico-chemical analyses. The results show that the plants grew for 2 weeks on regolith simulants. The leaves were bent downwards and chlorotic, the roots developed a lacunar aerenchyma and small brownish deposits containing Fe were observed. Gene expression analysis and proteomics revealed changes in transcripts related to the phenylpropanoid pathway, stress response, primary metabolism and proteins involved in translation and DNA methylation. Additionally, the growth of plants slightly but significantly modified the pH of the regolith simulants. The results here presented constitute a useful resource to get a comprehensive understanding of the major factors impacting the growth of plants on MMS-1.

Editorial for Special Issue: Research on Plant Cell Wall Biology

Plant cells are surrounded by extracellular matrixes [...].