This discovery offers brand-new insights into plant development and has significant implications for improving dry spell resistance in crops.A current research study released in Nature Plants by Chao Daiyins team at the Center for Excellence in Molecular Plant Sciences of the Chinese Academy of Sciences, along with Lyu Shiyous team at Hubei University, has revealed, for the first time, the secret behind the increase of seed plants from the perspective of specialized cell wall evolution.Seed plants are the most advanced plant group in the world, accounting for two-thirds of all plant species and forming the primary flora of our world. The evolutionary basis of suberin lamellae and their role in plant evolution had not yet been resolved.Evolutionary Insights into the Casparian Strip and Suberin LamellaeThis study utilized a series of innovative cell biology and analytical chemistry techniques to perform extensive research on agent plant types from 18 various evolutionary nodes with the objective of unveiling the tricks of the origin of the Casparian strip and suberin lamellae.Surprisingly, the scientists discovered that the Casparian strip exists in all vascular plants, consisting of ferns, angiosperms, gymnosperms, and lycophytes, while suberin lamellae are just present in gymnosperms and angiosperms (both collectively referred to as seed plants). The researchers revealed that the expanded homologous genes in gymnosperms and angiosperms could start suberin lamellae development, while the homologous genes in fern plants and lycophyte plants had no such function. Specifically, since water particles are capable of totally free diffusion across cell membranes in the lack of suberin lamellae, plants without suberin lamellae, such as ferns and horsetails, experience substantial water leak from endodermal cell membranes when subjected to osmotic stress, resulting in low transportation efficiency.Seed plants, with suberin lamellae totally enveloping their endodermal cells, practically completely obstruct the totally free diffusion of water particles. As a result, this research study has considerable implications for improving plant drought resistance, illuminating plant salt and drought tolerance systems, and establishing drought-resistant crop varieties.Reference: “The evolutionary innovation of root suberin lamellae contributed to the increase of seed plants” by Yu Su, Tao Feng, Chu-Bin Liu, Haodong Huang, Ya-Ling Wang, Xiaojuan Fu, Mei-Ling Han, Xuanhao Zhang, Xing Huang, Jia-Chen Wu, Tao Song, Hui Shen, Xianpeng Yang, Lin Xu, Shiyou Lü and Dai-Yin Chao, 6 November 2023, Nature Plants.DOI: 10.1038/ s41477-023-01555-1.
A new research study has actually exposed that the development of suberin lamellae in seed plants played a vital function in their dominance over ferns in Earths changing environment. This discovery provides brand-new insights into plant advancement and has substantial implications for improving dry spell resistance in crops.A recent study published in Nature Plants by Chao Daiyins team at the Center for Excellence in Molecular Plant Sciences of the Chinese Academy of Sciences, along with Lyu Shiyous group at Hubei University, has actually revealed, for the very first time, the secret behind the rise of seed plants from the point of view of specialized cell wall evolution.Seed plants are the most sophisticated plant group worldwide, accounting for two-thirds of all plant species and shaping the predominant plants of our world. However, the Earth was really different over 300 million years ago during the Carboniferous period, when ferns were the dominant plants, with towering tree ferns controling the eco-friendly landscape. Most of the coal resources on Earth today came from fern plants of that duration, hence the name “Carboniferous.” However, paleontological research reveals a turning point at the end of the Carboniferous duration, with Earths environment suddenly ending up being arid and cold. As a result, ferns began to decrease, paving the method for the increase of seed plants. However, this substantial evolutionary occasion is marked by numerous unsolved mysteries, with among the most crucial mysteries being: What specific advantages did seed plants develop that permitted them to transition from a weaker position to a prospering one by the end of the Carboniferous period?Key Findings on Plant Root StructuresRoots are important organs for transporting and soaking up water and mineral nutrients in plants, and the endodermis is the core of the root, managing water and mineral transportation. The endodermis cell wall includes a hydrophobic, lignin-based Casparian strip tightly anchored to the endodermal cell membrane, hence forming a barrier to avoid the totally free diffusion of substances. In addition, the suberin lamellae are specialized cell wall structures that cover the entire surface of endodermal cells.Research indicates that both the Casparian strip and suberin lamellae play important roles in plant nutrient balance and water transportation, however their functions are considerably various. Chaos group had actually previously made breakthroughs in understanding the development and anchoring of the Casparian strip. Nevertheless, the evolutionary basis of suberin lamellae and their function in plant advancement had actually not yet been resolved.Evolutionary Insights into the Casparian Strip and Suberin LamellaeThis research study used a series of advanced cell biology and analytical chemistry strategies to perform thorough research study on representative plant types from 18 various evolutionary nodes with the objective of revealing the tricks of the origin of the Casparian strip and suberin lamellae.Surprisingly, the scientists discovered that the Casparian strip exists in all vascular plants, including ferns, angiosperms, gymnosperms, and lycophytes, while suberin lamellae are only present in gymnosperms and angiosperms (both jointly referred to as seed plants). This proof recommends that the Casparian strip and suberin lamellae did not originate all at once; the former emerged from the common ancestor of all vascular plants, while the latter evolved in the common ancestor of seed plants. This finding challenges the longstanding presumption relating to suberin lamellae and offers brand-new viewpoints for studying the advancement of these structures.Gene Expansion and Suberin Lamellae in Seed PlantsTo investigate how suberin lamellae progressed in the typical forefather of seed plants, the scientists performed molecular evolutionary analyses of the genes involved in suberin lamellae formation and their homologs, with these outcomes: Although many of these genes had developed before the appearance of vascular plants, substantial expansion occurred in the common ancestor of seed plants. This growth recommended that gene duplication most likely resulted in practical innovations, thus making it possible for the genes responsible for manufacturing suberin lamellae to emerge in the typical ancestor of seed plants.To validate this hypothesis, the scientists examined homologous genes of the core MYB transcription factors involved in suberin development in fern plants, gymnosperms, lycophytes, and angiosperms. These genes were found to be widespread in all these plant groups. Nevertheless, a significant growth of homologous genes occurred in the typical forefather of gymnosperms and angiosperms. The scientists exposed that the expanded homologous genes in angiosperms and gymnosperms might initiate suberin lamellae development, while the homologous genes in fern plants and lycophyte plants had no such function. This finding confirmed that the function of MYB transcription aspects initiating suberin synthesis was acquired in seed plants through gene expansion.The Role of Suberin Lamellae in Plant AdaptationAs Earths environment ended up being dry in the late Carboniferous period, ferns started to decline and seed plants increased. Because suberin has waterproof homes, the scientists assumed that the emergence of suberin lamellae may have contributed to the dry spell flexibility of seed plants, thus promoting their rise after the start of arid conditions. They later verified this hypothesis by using 2 Arabidopsis hereditary materials with suberin defects, consequently showing that suberin-deficient Arabidopsis was more sensitive to drought.Furthermore, Raman spectroscopy and nuclear magnetic resonance revealed the essential significance of suberin lamellae in boosting the effectiveness of vascular water transport. Specifically, since water particles can complimentary diffusion throughout cell membranes in the absence of suberin lamellae, plants without suberin lamellae, such as ferns and horsetails, experience substantial water leakage from endodermal cell membranes when subjected to osmotic stress, resulting in low transportation efficiency.Seed plants, with suberin lamellae completely enveloping their endodermal cells, nearly entirely obstruct the free diffusion of water molecules. Hence, their water leakage rate under osmotic stress is just 1%– 2% compared to fern plants and lycophyte plants. This waterproofing result greatly improves the efficiency of water transport in the vascular tissues of seed plants under dry spell conditions, therefore increasing their dry spell resistance.Based on this, the researchers proposed a design for the rise of seed plants: In the damp climate of the Carboniferous duration, fern plants without any suberin lamellae had higher water and nutrient absorption performance and were better adapted to the environment, thus triggering them to prosper. However, during the late Carboniferous period, the start of a dry environment offered a benefit for seed plants that had actually developed suberin lamellae. They possessed a more effective water transport system and stronger dry spell tolerance, permitting them to gradually replace ferns and end up being the dominant life kinds on Earths surface.This study not only reveals the secret of the origin of the Casparian strip and suberin lamellae but likewise supplies proof, for the first time, that the introduction of suberin lamellae drove the increase of seed plants, based upon a new viewpoint. Furthermore, it identifies the important role of suberin lamellae in plant adaptation to unfavorable conditions such as drought. As an outcome, this study has substantial implications for boosting plant drought resistance, clarifying plant salt and drought tolerance mechanisms, and establishing drought-resistant crop varieties.Reference: “The evolutionary development of root suberin lamellae contributed to the rise of seed plants” by Yu Su, Tao Feng, Chu-Bin Liu, Haodong Huang, Ya-Ling Wang, Xiaojuan Fu, Mei-Ling Han, Xuanhao Zhang, Xing Huang, Jia-Chen Wu, Tao Song, Hui Shen, Xianpeng Yang, Lin Xu, Shiyou Lü and Dai-Yin Chao, 6 November 2023, Nature Plants.DOI: 10.1038/ s41477-023-01555-1.
