Cell identities along the proximal-distal and micropylar-chalazal axes in the Arabidopsis heart-stage seed

A single-nucleus transcriptomic atlas reveals distinct cell identities and key regulators of cellular differentiation during early rice seed development.

This study provides a single-cell resolution framework for understanding early rice seed development, identifies the embryo-endosperm interface as an important cellular domain associated with embryogenesis, and offers a valuable resource for dissecting the molecular basis of seed formation in rice and related cereals.

Control of plant organ growth linked to cell division orientation in inner tissues.

There is a dominant view that plants are shaped by the ability of their outermost cell layers to resist or yield to pressure from internal tissues. During stem development, outer tissues originate from the tunica layers of the shoot meristem, while inner tissues are produced by the rib zone (RZ), named after its distinctive pattern of transverse cell divisions. Despite over a century of studies, the interplay between inner and outer tissues in shaping the stem remains unclear. Here, we show that mutations in a subfamily of IQ domain (IQD) genes disrupt the orientation of cell divisions in the RZ and increase stem diameter in Arabidopsis. Measurements of cell geometry, growth of marked cell clones, tissue-specific expression, and subcellular localization all support the idea that these IQD proteins reduce longitudinal cell divisions in the RZ, limiting the build-up of vertical cell files in inner tissues and the concomitant radial growth of the stem. Thus, the characteristic orientation of cell divisions in the RZ is important for shaping the stem, and the genetic control of organ shape can be exerted in inner plant tissues.

Spatiotemporal Profiling of the Marchantia Sporophyte Reveals Ancestral Meristem Module and Dynamic Epigenetic Reprogramming during Early Embryogenesis

The cellular and genetic basis of inflorescence divergence between maize and teosinte

The domestication of maize from teosinte involved dramatic remodeling of the ear, yet the cellular and genetic bases of this transformation remain unclear. Here, we generate a single-nucleus and spatial transcriptome atlas of developing maize and teosinte ears. Comparative analysis reveals divergence in cob-associated cell types, with enhanced cytokinin signaling and reduced growth-inhibitory signals collectively driving cob thickening and enlargement in maize. We further demonstrate that domestication expanded the spatial expression domain of key transcription factors in maize meristem cells, enhancing the potential for increasing kernel number. Additionally, we verified a major domestication gene, ZmSPD1, in which two nonsynonymous SNPs differentiate maize from teosinte and alter jasmonic acid (JA) levels in the ear, thereby suppressing spikelet abortion to effectively double kernel production. These findings provide a cell-resolved mechanistic framework for how cob architecture and kernel number were shaped during maize domestication, offering new insights into the formation of key agronomic traits.

ERECTA signaling controls the timing of Arabidopsis Guard Cell maturation at the embryonic leaf tip

ERECTA signaling is identified as a local brake on embryonic stomatal cell maturation, discovering another way to push precocious stomatal cell maturation that results in a complex, partially mature cell state that provide insights into the limitations on cell embryonic cell maturation.

Spatial Transcriptomics in Plants: From Cellular Maps to Mechanistic Insight.

This review synthesizes recent progress across diverse plant species and tissues, showing that gene expression is not only cell-type specific but also tightly organized by position within organs and developmental niches, establishing spatial gene expression as a fundamental organizing principle of plant development and physiology.