scholarly journals Isolation and Functional Analysis of Drought-Induced Genes in Pinus

1993 ◽  
Author(s):  
Ronald Newton ◽  
Joseph Riov ◽  
John Cairney
Keyword(s):  
Cell Wall ◽  
Drought Stress ◽  
Loblolly Pine ◽  
Dna Sequences ◽  
Pinus Halepensis ◽  
Seedling Survival ◽  
Common Factor ◽  
Cdna Clones ◽  
Genomic Clones ◽  
Induced Genes

Drought is a common factor limiting timber production in the U.S. and Israel. Loblolly (Pinus taeda) and alleppo pine (Pinus halepensis) seedling survival is reduced when out planted, and growth and reproduction are often hindered by periodic droughts during later stages of tree development. Molecular and gene responses to drought stress have not been characterized. The objectives were to characterize drought-induced gene clones from these pines, to determine the effects of a growth regulator on drought tolerance, ABA levels, and drought-induced gene expression in alleppo pine, and to develop procedures for loblolly pine transformation. Nearly 20 cDNA clones influenced by gradual, prolonged drought stress have been isolated. Many of these have been shown to be induced by drought stress, whereas several others are down-regulated. These are the first drought-induced genes isolated from a pine species. Two genomic clones (lp5-1 and lp3-1) have been sequenced and characterized, and each has been found to be associated with a gene family. Clone lp5 appears to code for a cell wall protein, and clone lp3 codes for a nuclear protein. The former may be associated with changing the elastic properties of the cell wall, while the latter may be involved in signal transduction and/or protection from desiccation in the nucleus. Clone lp3 is similar to a drought-induced gene from tomato and is regulated by ABA. Several DNA sequences that are specific to induction during growth-retardation in alleppo pine by uniconazole have been identified. The active DNA species is now being identified. Promoters from genomic clones, lp3 and lp5, have been sequenced. Both are functional when fused with the gus reporter gene and transferred to other plant tissues as well as responding to a simulated drought stress. Through exodeletion analysis, it has been established that the promoter ABRE element of lp3 responds to ABA and that drought-induction of lp3 expression may also involve ABA. Stable tobacco transformants carrying either the lp5 or the lp3 promoter fused to a reporter gus gene have been obtained. The lp5lgus fusion was expressed at several stages of tobacco development and differentiation including the reproductive stage. There was no difference in phenotype between the transformants and the wild type. Embryogenesis procedures were developed for slash pine, but attempts to couple this process with gene transfer and plantlet transformation were not successful. Transformation of pine using Agrobacterium appears tractable, but molecular data supporting stable integration of the Agrobacterium-transferred gene are still inconclusive.

Multiple calmodulin mRNA species are derived from two distinct genes

1987 ◽  
Vol 7 (5) ◽  
pp. 1873-1880
Author(s):  
H Nojima ◽  
K Kishi ◽  
H Sokabe
Keyword(s):  
Dna Sequences ◽  
Northern Blotting ◽  
Amino Acid Sequences ◽  
Cdna Clones ◽  
Rat Tissues ◽  
Coding Region ◽  
Genomic Libraries ◽  
Mrna Species ◽  
Nuclease Mapping ◽  
Rat Genome

We have observed three calmodulin mRNA species in rat tissues. In order to know from how many expressed genes they are derived, we have investigated the genomic organization of calmodulin genes in the rat genome. From a rat brain cDNA library, we obtained two kinds of cDNAs (pRCM1 and pRCM3) encoding authentic calmodulin. DNA sequence analysis of these cDNA clones revealed substitutions of nucleotides at 73 positions of 450 nucleotides in the coding region, although the amino acid sequences of these calmodulins are exactly the same. DNA sequences in the 5' and 3' noncoding regions are quite different between these two cDNAs. From these results, we conclude that they are derived from two distinct bona fide calmodulin genes, CaMI (pRCM1) and CaMII (pRCM3). Total genomic Southern hybridization suggested four distinct calmodulin-related genes in the rat genome. By cloning and sequencing the calmodulin-related genes from rat genomic libraries, we demonstrated that the other two genes are processed pseudogenes generated from the CaMI (lambda SC9) and CaMII (lambda SC8) genes, respectively, through an mRNA-mediated process of insertions. Northern blotting showed that the CaMI gene is transcribed in liver, muscle, and brain in similar amounts, whereas the CaMII gene is transcribed mainly in brain. S1 nuclease mapping indicated that the CaMI gene produced two mRNA species (1.7 and 4 kilobases), whereas the CaMII gene expressed a single mRNA species (1.4 kilobases).

Wheat specific repetitive DNA sequences ? construction and characterization of four different genomic clones

1986 ◽  
Vol 72 (2) ◽  
pp. 207-210 ◽  
Author(s):  
M. Metzlaff ◽  
W. Troebner ◽  
F. Baldauf ◽  
R. Schlegel ◽  
J. Cullum
Keyword(s):  
Repetitive Dna ◽  
Dna Sequences ◽  
Repetitive Dna Sequences ◽  
Genomic Clones

scholarly journals Growth and Physiological Traits Associated with Drought Survival and Post-drought Recovery in Perennial Turfgrass Species

2010 ◽  
Vol 135 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Qi Chai ◽  
Fang Jin ◽  
Emily Merewitz ◽  
Bingru Huang
Keyword(s):  
Cell Wall ◽  
Drought Stress ◽  
Osmotic Adjustment ◽  
Perennial Grass ◽  
Kentucky Bluegrass ◽  
Physiological Traits ◽  
Grass Species ◽  
Cell Wall Elasticity ◽  
Drought Recovery ◽  
Drought Survival

The objective of this study was to determine physiological traits for drought survival and post-drought recovery upon re-watering in two C3 perennial grass species, kentucky bluegrass [KBG (Poa pratensis)] and perennial ryegrass [PRG (Lolium perenne)]. Plants were maintained well watered or exposed to drought stress by withholding irrigation and were then re-watered in a growth chamber. KBG had significantly higher grass quality and leaf photochemical efficiency, and lower electrolyte leakage than PRG during 20 days of drought. After 7 days of re-watering, drought-damaged leaves were rehydrated to the control level in KBG, but could not fully recover in PRG. KBG produced a greater number of new roots, while PRG had more rapid elongation of new roots after 16 days of re-watering. Superior drought tolerance in KBG was associated with osmotic adjustment, higher cell wall elasticity, and lower relative water content at zero turgor. Osmotic adjustment, cell wall elasticity, and cell membrane stability could play important roles in leaf desiccation tolerance and drought survival in perennial grass species. In addition, post-drought recovery of leaf hydration level and physiological activity could be associated with the accumulation of carbohydrates in leaves and rhizomes during drought stress and new root production after re-watering.

scholarly journals Survival of Longleaf and Loblolly Pines Planted at Two Spacings in an East Texas Bahiagrass Silvopasture

2008 ◽  
Vol 32 (1) ◽  
pp. 44-45
Author(s):  
Brian P. Oswald ◽  
Kenneth W. Farrish ◽  
Micah-John Beierle
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Seedling Survival ◽  
Survival Rates ◽  
Pinus Palustris ◽  
Mortality Rates ◽  
Paspalum Notatum ◽  
East Texas ◽  
Forage Production ◽  
Loblolly Pines

Abstract The practice of combining intensive timber and forage production on the same site, a silvopasture system, offers landowners the potential for diversification of income. The establishment of such a system in a pasture setting offers unique challenges compared with traditional timber or forage systems. In 2003, a silvopasture demonstration was established south of Carthage, Texas, in a pasture dominated by bahiagrass (Paspalum notatum). Four replications of treatments composed of open pasture, longleaf (Pinus palustris) and loblolly (Pinus taeda) pine planted at a traditional spacing, and longleaf and loblolly pine planted at a silvopasture spacing were established. Due to high mortality rates, replanting of trees occurred in 2004 and 2005. Third-year seedling survival was highest for loblolly pine in both planting systems, and forage production levels did not significantly differ among treatments. Wild hog damage contributed to the low longleaf pine seedling survival rates.

Functional genomics and cell wall biosynthesis in loblolly pine

2001 ◽  
pp. 275-291 ◽  
Author(s):  
Ross Whetten ◽  
Ying-Hsuan Sun ◽  
Yi Zhang ◽  
Ron Sederoff
Keyword(s):  
Cell Wall ◽  
Functional Genomics ◽  
Loblolly Pine ◽  
Cell Wall Biosynthesis

scholarly journals Needle-Clipping Longleaf Pine and Top-Pruning Loblolly Pine in Bareroot Nurseries

1998 ◽  
Vol 22 (4) ◽  
pp. 235-240 ◽  
Author(s):  
David B. South
Keyword(s):  
Loblolly Pine ◽  
Seedling Survival ◽  
Longleaf Pine ◽  
Weight Ratio ◽  
Dry Weight ◽  
Root Weight ◽  
Root Weight Ratio ◽  
Root Dry Weight ◽  
Percentage Points ◽  
Average Survival

Abstract Studies have shown that clipping needles of longleaf pine before outplanting can increase average seedling survival by 13 percentage points. Under some situations, the increase in survival might be due to a reduction in transpiration. For loblolly pine, top-pruning in the nursery might increase average survival by 6 percentage points. Benefits of pruning appear greater when seedlings experience stress after planting and when nonpruned seedlings have low root weight ratios (root dry weight/total seedling dry weight). On some droughty sites, a seedling with a 0.3 root weight ratio might have an 80% chance of survival, while a seedling with a 0.2 root weight ratio might only have a 53% chance of survival. In most studies where heights were measured after 3 yr in the field, pruned seedlings were the same height as nonpruned seedlings (± 7 cm). South. J. Appl. For. 22(4):235-240.

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