Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agriculture Sciences in Weifang, Weifang, Shandong 261325, China.
Beijing Genomics Institute Research, Beijing 102601, China.
Proc Natl Acad Sci U S A. 2023 Sep 19;120(38):e2310163120. doi: 10.1073/pnas.2310163120. Epub 2023 Sep 13.
Callus is a reprogrammed cell mass involved in plant regeneration and gene transformation in crop engineering. Pluripotent callus cells develop into fertile shoots through shoot regeneration. The molecular basis of the shoot regeneration process in crop callus remains largely elusive. This study pioneers the exploration of the spatial transcriptome of tomato callus during shoot regeneration. The findings reveal the presence of highly heterogeneous cell populations within the callus, including epidermis, vascular tissue, shoot primordia, inner callus, and outgrowth shoots. By characterizing the spatially resolved molecular features of shoot primordia and surrounding cells, specific factors essential for shoot primordia formation are identified. Notably, chlorenchyma cells, enriched in photosynthesis-related processes, play a crucial role in promoting shoot primordia formation and subsequent shoot regeneration. Light is shown to promote shoot regeneration by inducing chlorenchyma cell development and coordinating sugar signaling. These findings significantly advance our understanding of the cellular and molecular aspects of shoot regeneration in tomato callus and demonstrate the immense potential of spatial transcriptomics in plant biology.
愈伤组织是一种重编程的细胞团，参与作物工程中的植物再生和基因转化。多能性愈伤组织细胞通过芽再生发育成可育芽。作物愈伤组织中芽再生过程的分子基础在很大程度上仍难以捉摸。本研究率先探索了番茄愈伤组织在芽再生过程中的空间转录组。研究结果表明，愈伤组织内存在高度异质的细胞群体，包括表皮、维管束组织、芽原基、内愈伤组织和外芽。通过对芽原基和周围细胞的空间分辨分子特征进行表征，确定了芽原基形成所必需的特定因子。值得注意的是，富含光合作用相关过程的叶绿体细胞在促进芽原基形成和随后的芽再生中起着关键作用。光照通过诱导叶绿体细胞发育和协调糖信号转导来促进芽再生。这些发现显著提高了我们对番茄愈伤组织中芽再生的细胞和分子方面的理解，并展示了空间转录组学在植物生物学中的巨大潜力。
