Plant Biotechnology and Genetics: Principles, Techniques and Applications

stimulated with Br to turn on disease resistance pathways, cleverly showing that each part of
these receptors is specific and can function when swapped.
Activation of the BRI receptor is thought to stimulate other protein kinases and phospha-
tases that help relay information to the nucleus where the BES1 transcriptional activator acts
to regulate gene expression. In this way the Br signal transduction pathway is similar to
other signaling pathways we have examined, with a final nuclear transcriptional output
required for the final biological response to Br. It is interesting to note that there are over
170 genes inArabidopsispredicted to encode LRR kinases that may function in plant
signal transduction. In addition, there are several other putative receptor-like kinases that
do not contain LRR domains, but also may function in signaling.

4.7 Conclusions

Even though plants do not have elaborate body plans and the number of specialized cells as
organs compared with animals, developmental programs are no less elaborate. A number of
crucial plant growth regulators or hormones are required for proper plant growth. We will
see in the next chapter how plant biotechnologists can alter hormone type and concentration
to manipulate cells in petri dishes, a requirement for plant genetic transformation.

LIFE BOX 4.1. NATASHA RAIKHEL

Natasha Raikhel, University Distinguished Professor, Ernst and Helen

Leibacher Endowed Chair, University of California Riverside

Natasha Raikhel

I originated from and grew up in the

Soviet Union. I immigrated with my

husband and first born son to Athens,

Georgia in 1978 (my second son was

born in Athens, Georgia) with a personal

fortune of only $25. I remember feeling

somewhat lost and wondered how I

could and would ever make the

language, scientific and social tran-

sitions required of me. I did not realize

at the time that I was lucky in many

ways and that fortune had favored me.

I knew only one American scientist

when I first arrived, but I encountered

many helpful people that were critical

to my survival. I also entered a social

context within academia that differed in

several important ways from the system

I left behind. The American academic

system is characterized by greater diver-

sity and openness of thought and a

healthy atmosphere of competition that

drives one to take intellectual risks and

achieve more. At its best, this environ-

ment also leads to a constant renewal

of possibility, a wealth of new ideas

and a rich milieu of thoughtful exchange

that fosters both collective and individ-

ual progress. In America, I found a

place where prestige and intellectual

and economic rewards were all reason-

able potential goals. Although I did not

106 PLANT DEVELOPMENT AND PHYSIOLOGY