Winter Reading

[ChrisK]

I started skimming this paper and was thinking it seemed pretty "old school" in a lot of parts. Then I noticed it was published in 2004!

Originally Posted by Fusion_power

This article delves into the chemistry of cold tolerance in tomatoes. It is a fascinating article.
http://onlinelibrary.wiley.com/doi/1...4.02176.x/full

DarJones

[Fusion_power]

http://www.kurzweilai.net/editing-th...high-precision

This one points the way to the future. Targeted genetic tools are used to deliver a gene modification exactly where it is intended to go.

DarJones

[ChrisK]

All about plant transformation. I haven't read most of it so can't comment on the accuracy.

Genetic transformation of plants has revolutionized both basic and applied plant research. Plant molecular biology and physiology benefit from this power tool, as well as biotechnology. This book is a review of some of the most significant achievements that plant transformation has brought to the fields of Agrobacterium biology, crop improvement and, flower, fruit and tree amelioration. Also, it examines their impact on molecular farming, phytoremediation and RNAi tools.

http://www.intechopen.com/books/genetic-transformation

[ChrisK]

Screening of tomato genotypes for reproductive characters under high temperature stress conditions.

[ChrisK]

Paper from Jim Birchler on Heterosis since it's a topic in another thread.

Heterosis


HETEROSIS FOR YIELD COMPONENTS AND FRUIT CHARACTERS IN TOMATO

[ChrisK]

And a few more:

On epigenetics and epistasis: hybrids and their non-additive interactions



Extraordinary transgressive phenotypes of hybrid tomato are influenced by epigenetics and small silencing RNAs

[Fusion_power]

This is an article about tomato diseases by Vallad. Excellent because it has lots of large scale photos.

http://solutionsforyourlife.ufl.edu/...o-Diseases.pdf

DarJones

[Fred Hempel]

Awesome link. Thanks.

Originally Posted by Fusion_power

This is an article about tomato diseases by Vallad. Excellent because it has lots of large scale photos.

http://solutionsforyourlife.ufl.edu/...o-Diseases.pdf

DarJones

[Sun City Linda]

Those are the best pix of tomato disease I have ever seen! Thanks!

[Fusion_power]

This one is very thought provoking.

http://www.nature.com/news/do-plants...-genes-1.12401

[Redbaron]

Originally Posted by Fusion_power

This one is very thought provoking.

http://www.nature.com/news/do-plants...-genes-1.12401

Thought provoking for sure. Not sure if I even believe it. However, it would be an explanation of how sometimes a grafted plant occaisonally picks up a gene from the rootstock onto which it is grafted. Another unexplained phenomenon.

Hmmmmm

[bower]

Here are some links on earliness genetics:

http://tgc.ifas.ufl.edu/Vol48/Volume48.pdf

Mapping of earliness (er12.1) gene in tomato
Doganlar, S., Tanksley, S.D. and Mutschler, M.A.
Dept of Plant Breeding, Cornell University, Ithaca, NY 14853

"The most common form of earliness in tomatoes is early maturity due to an earlier switch from vegetative to reproductive growth. This type of earliness is generally measured by determining the number of days from
sowing to the appearance of the first ripe fruit (Kemple and Gardner 1992). Unfortunately, this type of earliness is associated with a decrease in fruit size (Banerjee and Kalloo 1989). A new form of earliness was identified in the 1980s in the variety 'Early Cherry' (M. Mutschler, pers. comm.). This type of early maturity is the result of a decreased length of time between anthesis and the first ripe fruit."
Results of mapping experiments:
"The QTL on chromosome 5 (er5.1) is also associated with fruit weight, but the QTL on chromosome 12 (er12.1) seems to be free of any associated
effect and may be useful in the development of early maturity lines."
------------------------------
http://www.springerlink.com/content/w276317744131215/
Perspectives of molecular marker assisted breeding for earliness in tomato
Pim Lindhout, Sjaak Heusden, Gerard Pet, Johan W. Ooijen, Hans Sandbrink, Ruud Verkerk, Ria Vrielink and Pim Zabel

"...three loci were identified that were associated with earliness. One was mainly associated with flowering time, another with fruitset time and a third one with ripening time. Two of these loci were also associated with fruit weight. F3 progenies selected for earliness on the basis of the QTL-data did confirm the F2 results. Two major earliness genes explained a difference in earliness of more than three weeks. The association with reduced fruit weight seemed to be due to pleiotropic effects rather than to linked genes."
------------------------------------------------
A classic paper (pre-molecular) reported similar results:
www.ncbi.nlm.nih.gov/pmc/articles/PMC1209491/pdf/363.pdf Fogle/Currence 1949
------------------------------------------------
http://www.springerlink.com/content/x245751n324281u1/
Evolution of early determinate tomato cultivars during the last three decades as a result of research conducted at Warsaw Agricultural University
Aleksandra Korzeniewska and Katarzyna Niemirowicz-Szczytt
- This names some cultivars which I haven't found in internet search.
-----------------------------------------------

[bower]

Cold tolerance genetics:

This is a really nice overview of stress response mechanisms:
http://jxb.oxfordjournals.org/content/63/4/1593.long
Drought, salt, and temperature stress-induced metabolic rearrangements and regulatory networks Julia Krasensky and Claudia Jonak

Another general article which gives an overview of present research:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3129041/
Engineering Cold Stress Tolerance in Crop Plants
Gulzar S Sanghera,1 Shabir H Wani,*,2 Wasim Hussain,1 and N.B Singh3
-------------------------------------
Cold tolerance genetics and cytoplasmic inheritance:

pubs.aic.ca/doi/pdf/10.4141/cjps80-022
Reciprocal cross analysis of growth component stages in tomatoes under two temperature regimes. Li TSC, Hornby CA
"The nuclear and cytoplasmic effects on seven growth component stages in tomatoes were studied in a reciprocal cross experiment involving two parental cultivars, Bonny Best and Immur Prior Beta, and their reciprocal hybrids. These were grown under the two temperature regimes in greenhouses, l7"C-21'C and lO"C-13"C respectively.
There was evidence that cytoplasmic effects were relatively important for some of the characteristics under stress temperature condition. It is suggested that the cytoplasmic effects and genic-cytoplasm interactions should be considered during selection for tomatoes under subnormal temperature conditions. "

pubs.aic.ca/doi/pdf/10.4141/cjps80-182
Li, T. S. C. (Li, S. C); Hornby, C. A., 1980: Reciprocal crosses analysis of three physiological characters in tomatoes under two temperature regimes. Canadian Journal of Plant Science 60(4): 1289-1293
"The nuclear and cytoplasmic effects in the net photosynthesis rate, leaf area and net assimilation rate in tomatos were studied in a reciprocal cross experiment involving two parental cultivars, Bonny Best and Immur Prior Beta, and their reciprocal hybrids. Plants were grown under two temperature regimes in growth chambers,23 + l'C and 12 -+ l'C, respectively. It was concluded that nuclear composition affected all three characters. Although the cytoplasmic effect sometimes revealed its influence, it was not large enough to warrent consideration in breeding studies."
--------------------------------------------------
www.publish.csiro.au/?act=view_file&file_id=SA0403661.pdf
Plastome from high-altitude Lycopersicon hirsutum does not improve
low-temperature tolerance of cold-sensitive Lycopersicon esculentum.
JH Venema, PR van Hasselt
"The results of this study show that the L. hirsutum plastome did not affect low temperature tolerance of photosynthesis in the tomato cybrid. This indicates that low temperature tolerance of photosynthesis is controled by the nuclear genome, which encodes 80−90% of the chloroplast proteins.....The observation that the cybrid was more susceptible to chill-induced photoinhibition of PSII than L. esculentum and L. hirsutum, suggested that cybridisation rendered the chloroplast more susceptible to light stress... In contrast to LRC and the cybrid, Pmax of L. hirsutum was significantly higher in response to growth at suboptimal temperature."

It's interesting that the cybrid was not very viable, some other work has also mentioned that rare recombinations of mtDNA have been observed in interspecies crosses, instead of the usual uniparental transmission. Possibly the genetic barriers to the crosses exist at the level of signalling between nuclear and cytoplasmic systems? (note Venema's work made a cybrid with the plastome, not mitochondria afaict)
----------------------------------
In peas, small HSP's, LEA and other stress response molecules are encoded in mtDNA and induced by cold stress in isolated mitochondria:

http://www.plantphysiol.org/content/140/1/326.full
----------------------------------------------------

[bower]

Glycinebetaine:

There is a lot of cold tolerance research presently focusing on this particular substance, which is an important osmolyte in crop plants such as barley, sugar beet and spinach. Some of the research is cited in the review linked above:
http://jxb.oxfordjournals.org/content/63/4/1593.long
Drought, salt, and temperature stress-induced metabolic rearrangements and regulatory networks Julia Krasensky and Claudia Jonak

Here are some links to research on glycinebetaine:

Glycinebetaine regulates tolerance of both drought and cold tolerance:
http://www.ncbi.nlm.nih.gov/pubmed/20946588

whether endogenous or externally applied/supplied. overview:
http://www.ncbi.nlm.nih.gov/pubmed/18703379

Genetic engineering of glycinebetaine synthesis in tomato protects seeds, plants, and flowers from chilling damage.
http://www.ncbi.nlm.nih.gov/pubmed/15500464
GMO research found GB expression in chloroplasts was more effective than in cytosol:
http://www.ncbi.nlm.nih.gov/pubmed/17617827
http://www.ncbi.nlm.nih.gov/pubmed/15500464
A full text on GB engineering in crops:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3329348/

Natural sources of glycinebetaine: seaweed
http://www.ncbi.nlm.nih.gov/pubmed/19363684 betaines in seaweed
http://www.ncbi.nlm.nih.gov/pubmed/10526988 nematode pest control associated with betaines incl gb in seaweed
http://www.ncbi.nlm.nih.gov/pubmed/19363684 lipophylic fraction and whole extract increased frost tolerance and activated genes

"In field-grown tomato subjected to salt or high temperature stress, fruit yields increased up to 39% following exogenous glycine betaine application at mid-flowering. In a previous study by Makela et al. (16) osmotic shock to plant foliage occurred when rates of application were too high, and this was more pronounced in plants that were not natural glycine betaine accumulators. "
http://www.plantmanagementnetwork.or.../2003/betaine/

Proline is an osmolyte that accumulates naturally in tomato, and high levels are found in pollen. The proline transporter in tomato pollen was also found to have a high affinity for glycine betaine (even higher than for proline itself). So tomato plants can readily take up gb and use it as an osmolyte, although not naturally produced/ accumulated in tomato stress response.
http://www.plantcell.org/content/11/3/377.full

[ChrisK]

It's certainly intriguing but it will require independent replication. Extraordinary claims require extraordinary proof. Passing peer review is only the first step and means it was deemed worthy (usually by three people) of publication and further discussion and investigation by other experts in the field.

Here is the full paper: http://f1000research.com/articles/2-5/v1

Originally Posted by Fusion_power

This one is very thought provoking.

http://www.nature.com/news/do-plants...-genes-1.12401