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21.
SCOTT SCHLOSSBERG DAVID I. KING RICHARD B. CHANDLER BENJAMIN A. MAZZEI 《The Journal of wildlife management》2010,74(7):1513-1522
Abstract: Shrubland birds are declining throughout the eastern United States. To manage scrub-shrub habitats for birds, managers need information on avian habitat relationships. Past studies have produced contradictory results in some cases and may be of limited generality because of site- and habitat-specific factors. We studied shrubland birds across 6 habitats in 3 New England states to provide more general information on habitat relationships than has been possible in past studies. Our study sites included all major scrub-shrub habitats in New England: wildlife openings, regenerating clear-cuts, beaver ponds, utility rights-of-way, pitch pine (Pinus rigida) woodlands, and scrub oak (Quercus ilicifolia) barrens and ranged from Connecticut to northern New Hampshire, with research conducted from 2002 to 2007. Using N-mixture models of repeated point counts, we found that 6 of 12 shrubland birds preferred areas with greater shrub cover. An additional 4 species appeared to prefer areas with lower-stature vegetation and greater forb cover. Eight of 10 bird species showed relationships with cover of individual plant species, with Spiraea spp., willows (Salix spp.), alders (Alnus spp.), and invasive exotics being the most important. We recommend that shrubland management for birds focus on providing 2 distinct habitats: 1) areas of tall (>1.5 m) vegetation with abundant shrub cover and 2) areas of lower (<1.5 m) vegetation with abundant forb cover but fewer shrubs. 相似文献
22.
Nitric oxide inhibits blue light-specific stomatal opening via abscisic acid signaling pathways in Vicia guard cells 总被引:6,自引:0,他引:6
Recent evidence suggests that nitric oxide (NO) acts as an intermediate of ABA signal transduction for stomatal closure. However, NO's effect on stomatal opening is poorly understood even though both opening and closing activities determine stomatal aperture. Here we show that NO inhibits stomatal opening specific to blue light, thereby stimulating stomatal closure. NO inhibited blue light-specific stomatal opening but not red light-induced opening. NO inhibited both blue light-induced H(+) pumping and H(+)-ATPase phosphorylation. The NO scavenger 2-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) restored all these inhibitory effects. ABA and hydrogen peroxide (H(2)O(2)) inhibited all of these blue light-specific responses in a manner similar to NO. c-PTIO partially restored the ABA-induced inhibition of all of these opening responses but did not restore inhibition of the responses by H(2)O(2). ABA, H(2)O(2) and NO had slight inhibitory effects on the phosphorylation of phototropins, which are blue light receptors in guard cells. NO inhibited neither fusicoccin-induced H(+) pumping in guard cells nor H(+) transport by H(+)-ATPase in the isolated membranes. From these results, we conclude that both NO and H(2)O(2) inhibit blue light-induced activation of H(+)-ATPase by inhibiting the component(s) between phototropins and H(+)-ATPase in guard cells and stimulate stomatal closure by ABA. 相似文献
23.
Lee Y Kim YW Jeon BW Park KY Suh SJ Seo J Kwak JM Martinoia E Hwang I Lee Y 《The Plant journal : for cell and molecular biology》2007,52(5):803-816
Previously, we demonstrated that a protein that binds phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P(2)] inhibits both light-induced stomatal opening and ABA-induced stomatal closing. The latter effect is due to a reduction in free PtdIns(4,5)P(2), decreasing production of inositol 1,4,5-trisphosphate and phosphatidic acid by phospholipases C and D. However, it is less clear how PtdIns(4,5)P(2) modulates stomatal opening. We found that in response to white light irradiation, the PtdIns(4,5)P(2)-binding domain GFP:PLCdelta1PH translocated from the cytosol into the plasma membrane. This suggests that the level of PtdIns(4,5)P(2) increases at the plasma membrane upon illumination. Exogenously administered PtdIns(4,5)P(2) substituted for light stimuli, inducing stomatal opening and swelling of guard cell protoplasts. To identify PtdIns(4,5)P(2) targets we performed patch-clamp experiments, and found that anion channel activity was inhibited by PtdIns(4,5)P(2). Genetic analyses using an Arabidopsis PIP5K4 mutant further supported the role of PtdIns(4,5)P(2) in stomatal opening. The reduced stomatal opening movements exhibited by a mutant of Arabidopsis PIP5K4 (At3g56960) was countered by exogenous application of PtdIns(4,5)P(2). The phenotype of reduced stomatal opening in the pip5k4 mutant was recovered in lines complemented with the full-length PIP5K4. Together, these data suggest that PIP5K4 produces PtdIns(4,5)P(2) in irradiated guard cells, inhibiting anion channels to allow full stomatal opening. 相似文献
24.
Maie T Meister AB Leonard GL Schrank GD Blob RW Schoenfuss HL 《Zoology (Jena, Germany)》2011,114(6):340-347
Differences in fiber type distribution in the axial muscles of Hawaiian gobioid stream fishes have previously been linked to differences in locomotor performance, behavior, and diet across species. Using ATPase assays, we examined fiber types of the jaw opening sternohyoideus muscle across five species, as well as fiber types of three jaw closing muscles (adductor mandibulae A1, A2, and A3). The jaw muscles of some species of Hawaiian stream gobies contained substantial red fiber components. Some jaw muscles always had greater proportions of white muscle fibers than other jaw muscles, independent of species. In addition, comparing across species, the dietary generalists (Awaous guamensis and Stenogobius hawaiiensis) had a lower proportion of white muscle fibers in all jaw muscles than the dietary specialists (Lentipes concolor, Sicyopterus stimpsoni, and Eleotris sandwicensis). Among Hawaiian stream gobies, generalist diets may favor a wider range of muscle performance, provided by a mix of white and red muscle fibers, than is typical of dietary specialists, which may have a higher proportion of fast-twitch white fibers in jaw muscles to help meet the demands of rapid predatory strikes or feeding in fast-flowing habitats. 相似文献
25.
Calcium changes and the response to methyl jasmonate in rice lodicules during anthesis 总被引:1,自引:0,他引:1
Summary. Potassium pyroantimonate precipitation was used to locate loosely bound calcium in rice (Oryza sativa L.) lodicules before and after anthesis, and flowering of panicles was accelerated by treatment with methyl jasmonate. From
1 day to 4 h before anthesis, the number of calcium precipitates in the cell walls and vacuole membranes decreased gradually,
whereas they increased remarkably in the cytoplasm and nucleolus. At the beginning of anthesis, the number of calcium granules
in lodicules reduced sharply, but there was a large accumulation of flocculent precipitates in the vacuoles. After anthesis,
the flocculent precipitates decreased in number until they disappeared, whereas the granular precipitates started to accumulate
once again. The rice florets treated with 2 mM methyl jasmonate were induced to open within 10–30 min and they then closed
0.5–1 h later. The nucleolus, cytoplasm, and vacuole membrane of the lodicule cells contained many calcium granules during
flowering, although the cell walls lacked calcium. At 1 h after treatment, the number of calcium granules had decreased, while
flocculent precipitates were regularly observed in the nondegenerated cells. At 6 h after treatment, calcium grains started
to reappear in the cell walls. These changes in calcium precipitates before and after anthesis indicate that the opening and
closing of florets correlates with the calcium level in lodicule cells. In addition, excised panicles, with florets judged
to be nearing anthesis, were soaked in 2–200 mM EGTA solution for 2 min after treatment with 2 mM methyl jasmonate. The results
indicate that EGTA had an antagonistic effect on the methyl jasmonate-induced floret opening in rice.
Correspondence and reprints: Key Laboratory of the Ministry of Education for Plant Developmental Biology, College of Life
Sciences, Wuhan University, Wuhan 430072, People’s Republic of China. 相似文献
26.
The purpose of this paper is to investigate the differential responses of flower opening to ethylene in two cut rose cultivars,
‘Samantha’, whose opening process is promoted, and ‘Kardinal’, whose opening process is inhibited by ethylene. Ethylene production
and 1-aminocyclopropane-1-carboxylate (ACC) synthase and oxidase activities were determined first. After ethylene treatment,
ethylene production, ACC synthase (ACS) and ACC oxidase (ACO) activities in petals increased and peaked at the earlier stage
(stage 3) in ‘Samantha’, and they were much more dramatically enhanced and peaked at the later stage (stage 4) in ‘Kardinal’
than control during vasing. cDNA fragments of three Rh-ACSs and one Rh-ACO genes were cloned and designated as Rh-ACS1, Rh-ACS2, Rh-ACS3 and Rh-ACO1 respectively. Northern blotting analysis revealed that, among three genes of ACS, ethylene-induced expression patterns of
Rh-ACS3 gene corresponded to ACS activity and ethylene production in both cultivars. A more dramatic accumulation of Rh-ACS3 mRNA was induced by ethylene in ‘Kardinal’ than that of ‘Samantha’. As an ethylene action inhibitor, STS at concentration
of 0.2 mmol/L generally inhibited the expression of Rh-ACSs and Rh-ACO in both cultivars, although it induced the expression of Rh-ACS3 transiently in ‘Kardinal’. Our results suggests that ‘Kardinal’ is more sensitive to ethylene than ‘Samantha’; and the changes
of Rh-ACS3 expression caused by ethylene might be related to the acceleration of flower opening in ‘Samantha’ and the inhibition in
‘Kardinal’. Additional results indicated that three Rh-ACSs genes were differentially associated with flower opening and senescence as well as wounding. 相似文献
27.
Popsavin V Benedeković G Popsavin M Srećo B Djoković D 《Carbohydrate research》2005,340(11):1866-1871
Methyl 2,3-anhydro-4-O-methanesulfonyl-alpha-d-ribopyranoside (12) was prepared through a new six-step sequence starting from d-arabinose. Chemical behaviour of 12 was further studied under solvolytic conditions and in the presence of azide anion as a nucleophile. Factors governing the regiochemistry of epoxide ring opening are briefly discussed. 相似文献
28.
29.
采用DDRT-PCR技术,以棉花盛花期项尖叶片cDNA为材料,对上海生物工程公司合成的专用于基因差异显示分析的3个锚定引物和全套26个随机引物进行筛选,最后选择了15个扩增差异带丰富的随机引物。采用3个锚定引物和这15个随机引物组成的45对引物组合对24个抗虫棉杂交组合及其10亲本盛花期叶片cDNA进行扩增和差显,2次扩增重复率达70.1%,表明在扩增过程中存在较高的假阳性,通过重复PCR扩增,统计稳定扩增的条带,可减少假阳性干扰。根据基因表达方式,将其划分5种模式:MI为双亲表达沉默,双亲出现条带而杂种没有条带;M2为单亲表达沉默,带仅出现在亲本之一,包括仅母本有带而父本和杂种无带和仅父本有带而母本和杂种无带2种表达方式:M3为杂种特异表达,带仅出现在杂种,双亲无带;M4为单亲表达一致,带在双亲之一和杂种中出现,而在另一亲本中不出现,包括母本、杂种中有带而父本无带和父本、杂种中有带而母本无带2种方式;M5为基因表达一致,带在双亲和杂种中均出现。差显表达模式比例与产量性状和杂种优势分析表明:M4与所有产量性状均呈正相关,并且与单位面积铃数相关达显著水平,其他各种模式与杂种产量性状表型值均未达到显著水平;M2与单位面积铃数杂种优势呈显著负相关,M3与皮棉产量杂种优势呈显著正相关。上述结果表明,盛花期叶片中的基因显性表达和杂种特异表达有利于产量形成和杂种优势发挥。 相似文献
30.
cDNAs of leaves of 24 pest-resistant cotton (authorization) crosses and their parents in full opening flower stages were amplified and different bands were displayed by DDRT-PCR, with 45 primer combinations. The mean percentage of bands duplicated was 70.1%, which implied that there was a high proportion of pseudopositive fragments in the amplified cDNA. These pseudopositive bands can be reduced using duplicate PCR. Correlation analysis between differential gene expression and hybrid performance and heterosis showed that M4 (bands detected in one parent and F1) was positively correlated with all yield traits, and significantly correlated with boll number; M2 (bands observed in one parent but not in F1 and another parent) was negatively correlated with heterosis of boll number; and M3 (bands observed only in F1) was positively correlated with heterosis of lint yield. These results showed that genes that had dominant and specific expression in top leaves of full opening flower stages were beneficial to yield formation and heterosis occurrence. 相似文献