Heterophylly is a phenomenon whereby an individual plant dramatically changes leaf shape in response to the surroundings. Hygrophila difformis (Acanthaceae; water wisteria), has recently emerged as a model plant to study heterophylly because of its striking leaf shape variation in response to various environmental factors. When submerged, H. difformis often develops complex leaves, but on land it develops simple leaves. Leaf complexity is also influenced by other factors, such as light density, humidity, and temperature. Here, we sequenced and assembled the H. difformis chromosome-level genome (scaffold N50: 60.43 Mb, genome size: 871.92 Mb), which revealed 36 099 predicted protein-coding genes distributed over 15 pseudochromosomes. H. difformis diverged from its relatives during the Oligocene climate-change period and expanded gene families related to its amphibious habit. Genes related to environmental stimuli, leaf development, and other pathways were differentially expressed in submerged and terrestrial conditions, possibly modulating morphological and physiological acclimation to changing environments. We also found that auxin plays a role in H. difformis heterophylly. Finally, we discovered candidate genes that respond to different environmental conditions and elucidated the role of LATE MERISTEM IDENTITY 1 (LMI1) in heterophylly. We established H. difformis as a model for studying interconnections between environmental adaptation and morphogenesis.
PLANT PHYSIOLOGY:西北农林揭示活性氧介导的抗柄锈菌的机制
Nucleotide-binding leucine-rich repeat (NLR) proteins 是胞内激活免疫反应的受体。本研究发现来自小麦的 wheat (Triticum aestivum) NLR protein Resistance Gene Analogs3 (TaRGA3)的表达受到柄锈菌的诱导, 从而触发cell death。Virus-induced gene silencing (VIGS) 和过表达分析证实，TaRGA3是通过促进活性氧的累积来提高植物对病害的抗性的。
蛋白互作分析证实，TaRGA3 与Ascorbate Peroxidase 6 (TaAPX6)互作，从而导致该酶活性下降. TaAPX6负调控小麦对柄锈菌的抗性，这与它可以清除活性氧有关，从而抑制了植物的超敏反应。
小结：本研究揭示了TaRGA3提高植物乃守护柄锈菌的机制。
原文：The wheat CC-NBS-LRR protein TaRGA3 confers resistance to stripe rust by suppressing Ascorbate peroxidase 6 activity
