LOP1: a gene involved in auxin transport and vascular patterning in Arabidopsis

We have taken a genetic approach to understanding the mechanisms that control vascular patterning in the leaves of higher plants. Here we present the identification and characterization of the lop1 mutant of Arabidopsis which is defective in basipetal transport of IAA. Mutant leaf midveins show disoriented axial growth, and bifurcation into twin veins that are frequently rotated out of the normal dorsal/ventral axis of the leaf. Mutant plants also display abnormal patterns of cell expansion in the midrib cortex and in the epidermis of the elongation zone of lateral roots. Lateral roots show abnormal curvature during initiation, sometimes encircling the primary root prior to growth in a normal downward direction. Mutant seedlings have normal levels of free IAA, and appear normal in auxin perception, suggesting that transport is the primary lesion. The abnormalities in vascular development, lateral root initiation and patterns of cell expansion observed in the lop] mutant are consistent with a basic disruption in basipetal transport of IAA.

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Genome-Wide Identification and Characterization of the FAR1/FHY3 Family in Populus trichocarpa Torr. & Gray and Expression Analysis in Light Response

Forests ◽

10.3390/f12101385 ◽

2021 ◽

Vol 12 (10) ◽

pp. 1385

Author(s):

Jiujun Du ◽

Lei Zhang ◽

Xiaolan Ge ◽

Xiaodong Xiang ◽

Demei Cao ◽

...

Keyword(s):

Regulatory Networks ◽

Higher Plants ◽

Populus Trichocarpa ◽

Expression Patterns ◽

Light Response ◽

Cis Acting ◽

Poplar Genome ◽

Genome Wide ◽

Identification And Characterization

Light is an important environmental factor for plant growth, and in higher plants, phytochrome A (phyA) is the predominant far-red photoreceptor, involved in various photoresponses. The FAR1/FHY3 transcription factor family, derived from transposases, is able to regulate plant development in response to multiple photosensitizers phytochrome. In total, 51 PtrFRSs were identified in the poplar genome, and were divided into 4 subfamilies. Among them, 47 PtrFRSs are located on 17 chromosomes. Upstream cis-acting elements of the PtrFRS genes were classified into three categories: growth and metabolism, stress and hormone, and the hormone and stress categories contained most of the cis-acting elements. Analysis of the regulatory networks and expression patterns showed that most PtrFRSs responded to changes in light intensity and were involved in the regulation of phytochromes. In this study, 51 PtrFRSs were identified and comprehensively bioinformatically analyzed, and preliminary functional analysis and prediction of PtrFRSs was carried out.

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Floral biology and characterization of seed germination in physic nut (Jatropha curcas L.)

Revista Brasileira de Sementes ◽

10.1590/s0101-31222012000400005 ◽

2012 ◽

Vol 34 (4) ◽

pp. 556-560 ◽

Cited By ~ 7

Author(s):

Beatriz Gonçalves Brasileiro ◽

Denise Cunha Fernandes dos Santos Dias ◽

Maria Carmen Bhering ◽

Luiz Antônio dos Santos Dias

Keyword(s):

Seed Germination ◽

Jatropha Curcas ◽

Lateral Roots ◽

Primary Root ◽

Floral Biology ◽

Minas Gerais State ◽

Normal Seedling ◽

Radicle Protrusion ◽

Secondary Roots

The objective of this study was to characterize morphologically the seed germination and floral biology of Jatropha curcas grown in Viçosa, Minas Gerais state. The floral biology study was made on fresh inflorescences of 20 plants. For the post-seminal development study, the seeds were submitted to laboratory and greenhouse germination test. J. curcas has flowers of both sexes within the same inflorescence, with each inflorescence having an average of 131 flowers, being 120 male and 10.5 female flowers. Low numbers of hermaphrodite flowers were also found, ranging from 0 to 6 flowers per inflorescence. The germination of J. curcas begins on the third day with radicle protrusion in the hilum region. The primary root is cylindrical, thick, glabrous and branches rapidly, with about 4-5 branches three days after protrusion, when the emergence of the secondary roots begins. Seed coat removal occurs around the 8th day, when the endosperm is almost totally degraded and offers no resistance to the cotyledons that expand between the 10th and 12th day. A normal seedling has a long greenish hypocotyl, two cotyledons, a robust primary root and several lateral roots. On the 12th day after sowing, the normal seedling is characterized as phanerocotylar and germination is epigeal.

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Identification and characterization of a spotted-leaf mutant spl40 with enhanced bacterial blight resistance in rice

Rice ◽

10.1186/s12284-019-0326-6 ◽

2019 ◽

Vol 12 (1) ◽

Cited By ~ 4

Author(s):

Atul Prakash Sathe ◽

Xiaona Su ◽

Zheng Chen ◽

Ting Chen ◽

Xiangjing Wei ◽

...

Keyword(s):

Bacterial Blight ◽

Blight Resistance ◽

Bacterial Blight Resistance ◽

Leaf Mutant ◽

Identification And Characterization

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Identification and Characterization of Genes Encoding the Hydroxypyruvate Reductases in Chlamydomonas Reveal Their Distinct Roles in Photorespiration

Frontiers in Plant Science ◽

10.3389/fpls.2021.690296 ◽

2021 ◽

Vol 12 ◽

Author(s):

Menglin Shi ◽

Lei Zhao ◽

Yong Wang

Keyword(s):

Higher Plants ◽

Crop Improvement ◽

Activity Measurement ◽

Quinone Oxidoreductase ◽

Hydroxypyruvate Reductase ◽

Eukaryotic Organism ◽

Genes Encoding ◽

Identification And Characterization ◽

Glyoxylate Reductase

Photorespiration plays an important role in maintaining normal physiological metabolism in higher plants and other oxygenic organisms, such as algae. The unicellular eukaryotic organism Chlamydomonas is reported to have a photorespiration system different from that in higher plants, and only two out of nine genes encoding photorespiratory enzymes have been experimentally characterized. Hydroxypyruvate reductase (HPR), which is responsible for the conversion of hydroxypyruvate into glycerate, is poorly understood and not yet explored in Chlamydomonas. To identify the candidate genes encoding hydroxypyruvate reductases in Chlamydomonas (CrHPR) and uncover their elusive functions, we performed sequence comparison, enzyme activity measurement, subcellular localization, and analysis of knockout/knockdown strains. Together, we identify five proteins to be good candidates for CrHPRs, all of which are detected with the activity of hydroxypyruvate reductase. CrHPR1, a nicotinamide adenine dinucleotide (NADH)-dependent enzyme in mitochondria, may function as the major component of photorespiration. Its deletion causes severe photorespiratory defects. CrHPR2 takes part in the cytosolic bypass of photorespiration as the compensatory pathway of CrHPR1 for the reduction of hydroxypyruvate. CrHPR4, with NADH as the cofactor, may participate in photorespiration by acting as the chloroplastidial glyoxylate reductase in glycolate-quinone oxidoreductase system. Therefore, the results reveal that CrHPRs are far more complex than previously recognized and provide a greatly expanded knowledge base for studies to understand how CrHPRs perform their functions in photorespiration. These will facilitate both modification of photorespiration and genetic engineering for crop improvement by synthetic biology.

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