Genetic Engineering of Plants Agricultural Research Opportunities and Policy Concerns (1984) / Chapter Skim
Currently Skimming:
A Tool for Fundamental Plant Science
A Tool for Fundamental Plant Science
Pages 27-32
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 27... ...
(The actual size of plant genomes vary greatly in size from one taxonomic group to the next.N To ciate onIv about a dozen plant genes ~ 1 , , , have been fully sequenced. As GoIciberg clescribecT, molecular biologists are learning that the organization of the plant genome is also exceecTingly complex.
|
From page 28... ...
Worms Molds Algae Fungi Gram-positive bacteria Gram-negative bacteria Mycoplasma GENETIC ENGINEERING OF PLANTS SIZE OF PLANT GENOMES 5X102 5x103 5x104 5x105 5X106 5x107 I .
|
From page 29... ...
The next question, Goldberg said, is the extent to which these genes are reguiatect in the plant: "Do all these organ systems have 100,000 genes that are on and active, or is there a differential gene expression that could contribute to the differentiated state of the particular cell? " In the tobacco plant, approximately 25,000 genes are on in each organ
|
From page 30... ...
~ . GENETIC ENGINEERING OF PLANTS 1~\ _ ; ·:.:::- ::::: ·: -:::~~ mN 0^ ~ ~0 Genes Expressed Only in One Organ Genes Expressed in Two or More Organs Housekeeping Genes Expressed in All Organs 30,000 25,000 20,000 15,000 1 0,000 5,000 In LL Ad UJ o LLJ m me Gene expression is under complex control in higher plants.
|
From page 31... ...
The central task in both molecular and developmental biology is to understand the regulatory controls responsible for differential gene expression during development to find the DNA sequences that instruct a gene to be on in a leaf but off in a root. Only when these DNA sequences have been identified can molecular biologists use gene-splicing techniques with predictability to engineer new crop plants.
|
From page 32... ...
They have found that it contains three introns, or noncoding sequences, anc! they have located the regulatory sequences responsible for excising those introns in the natural cut-andpaste reaction.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.