The ABA-AtNAP-SAG113 PP2C module regulates leaf senescence by dephoshorylating SAG114 SnRK3.25 in Arabidopsis.

We previously reported that ABA inhibits stomatal closure through AtNAP-SAG113 PP2C regulatory module during leaf senescence. The mechanism by which this module exerts its function is unknown. Here we report the identification and functional analysis of SAG114, a direct target of the regulatory module.

Warming-induced changes of broccoli head to cauliflower-like curd in Brassica oleracea are regulated by DNA methylation as revealed by methylome and transcriptome co-profiling.

Increasingly warming temperature impacts on all aspects of growth and development in plants. Flower development is a complex process that is very sensitive to ambient temperature, and warming temperatures often lead to abnormal flower development and remarkably reduce the quality and yield of inflorescent vegetables and many other crops, which can be exemplified by Brassica oleracea cv. Green Harmony F1, a broccoli cultivar, whose floral development is ceased at inflorescence meristem (at 28 °C) or floral primordium stage (at 22 °C), forming a cauliflower-like curd (28 °C) or intermediate curd (22 °C) instead of normal broccoli head at 16 °C.

Ethylene controls cambium stem cell activity via promoting local auxin biosynthesis.

The vascular cambium is the main secondary meristem in plants that produces secondary phloem (outside) and xylem (inside) on opposing sides of the cambium. The phytohormone ethylene has been implicated in vascular cambium activity, but the regulatory network underlying ethylene-mediated cambial activity remains to be elucidated. Here, we found that PETAL MOVEMENT-RELATED PROTEIN1 (RhPMP1), an ethylene-inducible HOMEODOMAIN-LEUCINE ZIPPER I transcription factor in woody plant rose (Rosa hybrida), regulates local auxin biosynthesis and auxin transport to maintain cambial activity.

A positive feedback regulatory loop, SA-AtNAP-SAG202/SARD1-ICS1-SA, in SA biosynthesis involved in leaf senescence but not defense response.

Salicylic acid (SA) is an important plant hormone that regulates defense responses and leaf senescence. It is imperative to understand upstream factors that regulate genes of SA biosynthesis. SAG202/SARD1 is a key regulator for isochorismate synthase 1 (ICS1) induction and SA biosynthesis in defense responses.

The circadian-controlled PIF8-BBX28 module regulates petal senescence in rose flowers by governing mitochondrial ROS homeostasis at night.

Reactive oxygen species (ROS) are unstable reactive molecules that are toxic to cells. Regulation of ROS homeostasis is crucial to protect cells from dysfunction, senescence, and death. In plant leaves, ROS are mainly generated from chloroplasts and are tightly temporally restricted by the circadian clock.

AUXIN RESPONSE FACTOR 18-HISTONE DEACETYLASE 6 module regulates floral organ identity in rose (Rosa hybrida).

The phytohormone auxin plays a pivotal role in floral meristem initiation and gynoecium development, but whether and how auxin controls floral organ identity remain largely unknown. Here, we found that auxin levels influence organ specification, and changes in auxin levels influence homeotic transformation between petals and stamens in rose (Rosa hybrida). The PIN-FORMED-LIKES (PILS) gene RhPILS1 governs auxin levels in floral buds during floral organogenesis.

Ethylene-regulated asymmetric growth of the petal base promotes flower opening in rose (Rosa hybrida).

Flowers are the core reproductive structures and key distinguishing features of angiosperms. Flower opening to expose stamens and gynoecia is important in cases where pollinators much be attracted to promote cross-pollination, which can enhance reproductive success and species preservation. The floral opening process is accompanied by the coordinated movement of various floral organs, particularly petals.

Regulation of Leaf Longevity by DML3-Mediated DNA Demethylation.

Leaf senescence is driven by the expression of senescence-associated genes (SAGs). Development-specific genes often undergo DNA demethylation in their promoter and other regions, which regulates gene expression. Whether and how DNA demethylation regulates the expression of SAGs and thus leaf senescence remain elusive.

In rose, transcription factor PTM balances growth and drought survival via PIP2;1 aquaporin.

Plants have evolved sophisticated systems in response to environmental changes, and growth arrest is a common strategy used to enhance stress tolerance. Despite the growth-survival trade-off being essential to the shaping of plant productivity, the mechanisms balancing growth and survival remain largely unknown. Aquaporins play a crucial role in growth and stress responses by controlling water transport across membranes.

Maintenance of grafting-induced epigenetic variations in the asexual progeny of Brassica oleracea and B. juncea chimera.

Grafting-induced variations have been observed in many plant species, but the heritability of variation in progeny is not well understood. In our study, adventitious shoots from the C cell lineage of shoot apical meristem (SAM) grafting chimera TCC (where the origin of the outmost, middle and innermost cell layers, respectively, of SAM is designated by 'T' for tuber mustard and 'C' for red cabbage) were induced and identified as r-CCC (r = regenerated). To investigate the maintenance of grafting variations during cell propagation and regeneration, different generations of asexual progeny (r-CCCn, n = generation) were established through successive regeneration of axillary shoots from r-CCC.

Concepts and Types of Senescence in Plants.

Concepts, classification, and the relationship between different types of senescence are discussed in this chapter. Senescence-related terminology frequently used in yeast, animal, and plant systems and senescence processes at cellular, organ, and organismal levels are clarified.

Encodes a Salicylic Acid 5-Hydroxylase That Fine-Tunes Salicylic Acid Homeostasis.

The phytohormone salicylic acid (SA) plays essential roles in biotic and abiotic responses, plant development, and leaf senescence. 2,5-Dihydroxybenzoic acid (2,5-DHBA or gentisic acid) is one of the most commonly occurring aromatic acids in green plants and is assumed to be generated from SA, but the enzymes involved in its production remain obscure. DMR6 (Downy Mildew Resistant6; At5g24530) has been proven essential in plant immunity of Arabidopsis (), but its biochemical properties are not well understood.

Differential DNA methylation and gene expression in reciprocal hybrids between Solanum lycopersicum and S. pimpinellifolium.

Wide hybridization is a common and efficient breeding strategy for enhancing crop yield and quality. An interesting phenomenon is that the reciprocal hybrids usually show different phenotypes, and its underlying mechanism is not well understood. Here, we reported our comparative analysis of the DNA methylation patterns in Solanum lycopersicum, Solanum pimpinellifolium and their reciprocal hybrids by methylated DNA immunoprecipitation sequencing.

Proteomic Analysis of Hylocereus polyrhizus Reveals Metabolic Pathway Changes.

Red dragon fruit or red pitaya () is the only edible fruit that contains betalains. The color of betalains ranges from red and violet to yellow in plants. Betalains may also serve as an important component of health-promoting and disease-preventing functional food.

Translational researches on leaf senescence for enhancing plant productivity and quality.

Leaf senescence is a very important trait that limits yield and biomass accumulation of agronomic crops and reduces post-harvest performance and the nutritional value of horticultural crops. Significant advance in physiological and molecular understanding of leaf senescence has made it possible to devise ways of manipulating leaf senescence for agricultural improvement. There are three major strategies in this regard: (i) plant hormone biology-based leaf senescence manipulation technology, the senescence-specific gene promoter-directed IPT system in particular; (ii) leaf senescence-specific transcription factor biology-based technology; and (iii) translation initiation factor biology-based technology.

Salicylic acid 3-hydroxylase regulates Arabidopsis leaf longevity by mediating salicylic acid catabolism.

The plant hormone salicylic acid (SA) plays critical roles in plant defense, stress responses, and senescence. Although SA biosynthesis is well understood, the pathways by which SA is catabolized remain elusive. Here we report the identification and characterization of an SA 3-hydroxylase (S3H) involved in SA catabolism during leaf senescence.

SAUR36, a small auxin up RNA gene, is involved in the promotion of leaf senescence in Arabidopsis.

Small Auxin Up RNA genes (SAURs) are early auxin-responsive genes, but whether any of them are involved in leaf senescence is not known. Auxin, on the other hand, has been shown to have a role in leaf senescence. Some of the external application experiments indicated that auxin can inhibit leaf senescence, whereas other experiments indicated that auxin can promote leaf senescence.

Arabidopsis AtNAP regulates fruit senescence.

Arabidopsis has been used as a model system to study many aspects of plant growth and development. However, fruit senescence in Arabidopsis has been less investigated and the underlying molecular and hormonal (especially ethylene) regulatory mechanisms are not well understood. It is reported here that the Arabidopsis silique has characteristics of a climacteric fruit, and that AtNAP, a NAC family transcription factor gene whose expression is increased with the progression of silique senescence, plays an important role in its senescence.