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Conifers are long-lived organisms, and part of their success is due to their potent defense mechanisms. This review focuses on bark defenses, a front line against organisms trying to reach the nutrient-rich phloem. A major breach of the bark can lead to tree death, as evidenced by the millions of trees killed every year by specialized bark-invading insects.(More)
Calcium oxalate (CaOx) crystals are distributed among all taxonomic levels of photosynthetic organisms from small algae to angiosperms and giant gymnosperms. Accumulation of crystals by these organisms can be substantial. Major functions of CaOx crystal formation in plants include high-capacity calcium (Ca) regulation and protection against herbivory.(More)
The leaf sucrose transporter SUT1 is essential for phloem loading and long-distance transport of assimilates. Both SUT1 messenger RNA (mRNA) and protein were shown to be diurnally regulated and to have high turnover rates. SUT1 protein was detected by immunolocalization in plasma membranes of enucleate sieve elements (SEs) in tobacco, potato, and tomato.(More)
Rice prolamines are sequestered within the endoplasmic reticulum (ER) lumen even though they lack a lumenal retention signal. Immunochemical and biochemical data show that BiP, a protein that binds lumenal polypeptides, is localized on the surface of the aggregated prolamine protein bodies (PBs). BiP also forms complexes with nascent chains of prolamines in(More)
CmPP16 from Cucurbita maxima was cloned and the protein was shown to possess properties similar to those of viral movement proteins. CmPP16 messenger RNA (mRNA) is present in phloem tissue, whereas protein appears confined to sieve elements (SE). Microinjection and grafting studies revealed that CmPP16 moves from cell to cell, mediates the transport of(More)
Sucrose transport from the apoplasm, across the plasma membrane, and into the symplast is critical for growth and development in most plant species. Phloem loading, the process of transporting sucrose against a concentration gradient into the phloem, is an essential first step in long-distance transport of sucrose and carbon partitioning. We report here(More)
The efficiency of photosynthetic carbon assimilation in higher plants faces significant limitations due to the oxygenase activity of the enzyme Rubisco, particularly under warmer temperatures or water stress. A drop in atmospheric CO(2) and rise in O(2) as early as 300 mya provided selective pressure for the evolution of mechanisms to concentrate CO(2)(More)
Developing rice endosperm cells display two distinct rough endoplasmic reticula (ER), cisternal ER (C-ER) and protein body ER (PB-ER), the latter delimiting the prolamine protein bodies. These ER membranes are utilized for the simultaneous synthesis of glutelin and prolamine storage proteins, which are subsequently routed into separate protein bodies. We(More)
Wounding of Norway spruce by inoculation with sterile agar, or agar containing the pathogenic fungus Ceratocystis polonica, induced traumatic resin duct formation in the stem. Visible anatomical responses occurred in the cambium 6-9 d post-inoculation. Near the inoculation site cellular proliferation, polyphenolic accumulation, and lignification were(More)
Application of 100 mmol/L methyl jasmonate (MJ) to the intact bark of 30-yr-old Norway spruce induced anatomical reactions related to defense. Within 30 d, a single MJ treatment induced swelling of existing polyphenolic parenchyma cells (PP cells) and an increase in their phenolic contents and formation of additional PP cells and of traumatic resin ducts(More)