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Langballe Blevins posted an update 1 week, 1 day ago
These results suggest that autophagy is required for proper regulation of gene expression and quality control of organelles and timely progression of tapetal PCD during rice pollen development. Copyright © 2020 Hanamata, Sawada, Ono, Ogawa, Fukunaga, Nonomura, Kimura, Kurusu and Kuchitsu.FES1A is a heat shock protein 70 binding protein. Mutation of FES1A leads to a defect in thermotolerance of Arabidopsis; however, independent fes1a mutants exhibit a range in the extent of thermosensitivity. Here, we found that BRF2, a gene adjacent to FES1A and encoding a component of transcription factor IIIB, affects the thermosensitivity of fes1a mutants. Knockout of BRF2 suppressed fes1a thermosensitivity, while overexpression of BRF2 increased thermosensitivity of fes1a. BRF2 in fes1a mutants regulates the transcriptional strength of RNA Polymerase II and accumulation of heat shock proteins and eventually affects the thermotolerance of fes1a. There is a cross-talking between RNA Pol III and Pol II. The cross-talking is initiated by BRF, magnified by the mutation of FES1A, and finally has an effect on thermotolerance. Copyright © 2020 Fu, Liu, Li, Huo, Ge, Hou, Yang, Zhang, Zhang, Zhao, Ma and Liu.Important advances have been made in understanding the relationship of necrotrophic effectors (NE) and host sensitivity (Snn) genes in the Parastagonospora nodorum-wheat pathosystem. Yet much remains to be learned about the role of these interactions in determining wheat resistance levels in the field, and there is mixed evidence on whether breeding programs have selected against Snn genes due to their role in conferring susceptibility. SNB occurs ubiquitously in the U.S. Atlantic seaboard, and the environment is especially well suited to field studies of resistance to natural P. nodorum populations, as there are no other important wheat leaf blights. Insights into the nature of SNB resistance have been gleaned from multi-year data on phenotypes and markers in cultivars representative of the region’s germplasm. In this perspective article, we review the evidence that in this eastern region of the U.S., wheat cultivars have durable quantitative SNB resistance and Snn-NE interactions are of limited importance. This conclusion is discussed in light of the relevant available information from other parts of the world. Copyright © 2020 Cowger, Ward, Brown-Guedira and Brown.Heat stress negatively affects photosynthesis in crop plants. Chlorophyll fluorescence provides information about the efficiency of the light-dependent reactions of photosynthesis and can be measured non-destructively and rapidly. Four soybean (Glycine max) genotypes were grown in controlled environments at 28/20°C (control), followed by imposition of control, 38/28°C, and 45/28°C day/night temperature regimes for 7 days. Coordinated chlorophyll fluorescence, gas exchange, and chloroplast ultrastructure measurements were conducted over the course of the 7-day temperature treatments and revealed contrasting responses among the different genotypes. Although generally similar, the extent of the impact of elevated temperatures on net photosynthesis differed among genotypes. Despite dramatic effects on photosynthetic light reactions, net photosynthetic rates were not reduced by exposure to 45°C on the 1st day of treatment imposition. Temporal dynamics of light reaction characteristics over the course of the 7-day more tolerant soybean cultivars and to facilitate the dissection of molecular mechanisms underpinning heat stress tolerance of soybean photosynthesis. check details Copyright © 2020 Herritt and Fritschi.Variations of photosynthetic structures in different tissues or cells are in coordination with changes in various aspects, e.g. physiology, biochemistry, gene expression, etc. Most C4 plant species undergo developmental enhancement of the photosynthetic system, which may present different modes of changes between anatomy and physiology/biochemistry. In the current study, we investigated a Kranz-type C4 species Salsola ferganica with the progressive development of photosynthetic (PS) structure, performance of PS physiology, induction of PS enzymes, and transcriptional and translational regulation of PS genes, results revealed that S. ferganica presented C3 type anatomy in cotyledons but C4 type in leaves (C3/L4), with the C4 system separation of initial carbon fixation in the palisade mesophyll (M) cells and the following incorporation into triosephosphates and sugars in the bundle sheath (BS) cells, respectively. The BS cells continuously surrounded the vascular bundles and water storage cells in leaf anatomic structure. Compared to the single-cell C4 species Suaeda aralocaspica, S. ferganica exhibited similar developmental enhancement of C4 syndrome temporally and spatially in anatomic structures, enzyme activities, and gene expression, which suggests that completion of differentiation of the photosynthetic system is necessary for a C4 assimilation pathway. Besides, S. ferganica also displayed some different characteristics compared to S. aralocaspica in photosynthetic physiology, e.g. a more flexible δ13C value, much lower phosphoenolpyruvate carboxylase (PEPC) activity, and an insensitive response to stimuli, etc., which were not typical C4 characteristics. We speculate that this may suggest a different status of these two species in the evolutionary process of the photosynthesis pathway. Our findings will contribute to further understanding of the diversity of photosynthesis systems in Kranz-type C4 species and the Salsola genus. Copyright © 2020 Liu, Maimaitijiang, Zhang, Ma and Lan.The Millettioid/Phaseoloid (MP) clade from the subfamily Papilionoideae (Leguminosae) consists of six tribes and ca. 3,000 species. Previous studies have revealed some plastome structural variations (PSVs) within this clade. However, many deep evolutionary relationships within the clade remain unresolved. Due to limited taxon sampling and few genetic markers in previous studies, our understanding of the evolutionary history of this clade is limited. To address this issue, we sampled 43 plastomes (35 newly sequenced) representing all the six tribes of the MP clade to examine genomic structural variations and phylogenetic relationships. Plastomes of the species from the MP clade were typically quadripartite (size ranged from 140,029 to 160,040 bp) and contained 109-111 unique genes. We revealed four independent gene losses (ndhF, psbI, rps16, and trnS-GCU), multiple IR-SC boundary shifts, and six inversions in the tribes Desmodieae, Millettieae, and Phaseoleae. Plastomes of the species from the MP clade have experienced significant variations which provide valuable information on the evolution of the clade.