Ex Parte Gepstein et al

Patent Trial and Appeal Board

Oct 5, 2016

11909262 (P.T.A.B. Oct. 5, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
111909,262 05/12/2008
20350 7590 10/07/2016
KILPATRICK TOWNSEND & STOCKTON LLP
Mailstop: IP Docketing - 22
1100 Peachtree Street
Suite 2800
Atlanta, GA 30309
Shimon Gepstein
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www .uspto.gov
ATTORNEY DOCKET NO. CONFIRMATION NO.
81906-735612 (158910US) 3429
EXAMINER
KUMAR, VINOD
ART UNIT PAPER NUMBER
1663
NOTIFICATION DATE DELIVERY MODE
10/07/2016 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address( es):
ipefiling@kilpatricktownsend.com
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PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte SHIMON GEPSTEIN, AMIRA GEPSTEIN,
and EDUARDO BLUMW ALD 1
Appeal2014-007925
Application 11/909,262
Technology Center 1600
Before ERIC B. GRIMES, JOHN E. SCHNEIDER,
and TIMOTHY G. MAJORS, Administrative Patent Judges.
MAJORS, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims to methods
of preparing drought-resistant plants which have been rejected as obvious.
We have jurisdiction under 35 U.S.C. § 6(b).
We reverse.
1 Appellants identify the Regents of the University of California as
Represented by UC Davis Innovation Access and Technion Research and
Development Foundation. (App. Br. 3.)
Appeal2014-007925
Application 11/909,262
STATEMENT OF THE CASE
According to the Specification: (i) "'senescence' (also referred to as
programmed cell death) refers to a genetically controlled, active process by
which plant cells and tissues loose [sic, lose] organization and function" and
(ii) "IPT [isopentenyl transferase] is known to increase the level of
cytokinin, a class of plant hormones the concentration of which declines
during senescense and thus may play a role in controlling leaf senescence."
(Spec. i-fi-15, 19.) "The present invention relates to the development of
drought-resistant plants ... [by] preparation of transgenic plants that express
a protein [e.g., IPT] involved in cytokinin synthesis under the control of a
senescence-inducible promoter." (Id. at i19; see also id. at i133).
Claims 1, 3, and 5-12 are on appeal. Claim 1 is illustrative:
1. A method of preparing a transgenic plant resistant
to drought stress, the method comprising:
(a) transforming a population of plants with a recombinant
expression cassette comprising a senescence-associated receptor
kinase (SARK) promoter from Phaseolus vulgaris operably
linked to a nucleic acid sequence encoding a protein involved in
cytokinin synthesis; and
(b) selecting a transgenic plant that comprises the
recombinant expression cassette and is resistant to drought stress,
wherein the drought stress causes severe irreversible wilting in
a plant that lacks the recombinant expression cassette.
(App. Br. 17 (Claims App'x).)
2
Appeal2014-007925
Application 11/909,262
The claims stand rejected as follows:
Claims 1, 3, 5-7, and 9-12 under 35 U.S.C. § 103(a) over Gepstein,2
Synkova, 3 and Clark. 4
Claim 8 under 35 U.S.C. § 103(a) over Gepstein, Synkova, and Clark,
in further view of Zinselmeier. 5
DISCUSSION
Claim 1 is the only independent claim on appeal, and it relates to a
drought assay for transgenic plants. In a first step, a population of plants is
genetically transformed with a recombinant expression cassette comprising a
senescence-associated receptor kinase ("SARK") promoter linked to a
nucleic acid sequence encoding a protein (e.g., IPT) involved in cytokinin
synthesis. In a second step, a transgenic plant is selected for its resistance to
drought stress that causes severe irreversible wilting in plants lacking the
particular genetic modification.
The Examiner concludes method claim l would have been obvious
over Gepstein, Synkova, and Clark.
According to the Examiner,
Gepstein et al. teach a method of preparing a transgenic plant
comprising introducing and expressing . . . in a plant a
recombinant expression cassette comprising a SARK . . .
2 Gepstein et al., WO 99/29159, published June 17, 1999 ("Gepstein").
3 Synkova et al., Response to mild water stress in transgenic Pssu-ipt
tobacco, 112 PHYSIOLOGIAPLANTARUM 513-523 (2001) ("Synkova").
4 Clark et al., Drought-induced Leaf Senescence and Horticultural
Performance of Transgenic PsAa12-IPT Petunias, 129: 1 J. AMER. Soc. HORT.
Sci. 93-99 (2004) ("Clark").
5 Zinselmeier et al., WO 03/087313 A2, published Oct. 23, 2003
("Zinselmeier").
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Appeal2014-007925
Application 11/909,262
promoter operably linked to the isopentenyl transferase (ipt)
coding sequence from Agrobacterium . ... [and further teaches]
said SARK gene is from Phaseolus vulgaris.
(Ans. 4.) In other words, the Examiner finds Gepstein teaches the first step,
(step "(a)"), of claim 1.
The Examiner finds, however, that Gepstein does "not teach selecting
their transgenic plants for drought stress tolerance or resistance" and thus
turns to Synkova and Clark. (Ans. 5.) According to the Examiner,
Synkova et al. teach a method of producing transgenic plants
comprising overexpressing a nucleotide sequence encoding
isopentenyl transferase (IPT) protein from a promoter, and which
resulted in enhanced drought tolerance to the transgenic plants.
See in particular, abstract, page 516, figures 1-2.
(Id.) As to Clark, the Examiner finds it "teach[ es] that drought stress
induces senescence in plants .... [and] that transgenic plants overexpressing
IPT protein exhibited more than 50 fold increase in ipt transcript under
drought stress conditions." (Id.)
In view of these teachings, the Examiner concludes "it would have
been obvious ... to have screened Gepstein et al. transgenic plants for
improved drought stress tolerance and thus arrive at the Appellant's
invention with a reasonable expectation of success." (Id. at 6.)
We are not persuaded that the Examiner has met the burden to
demonstrate that claim 1 would have been obvious. Although we agree with
the Examiner that Gepstein teaches step (a) of claim 1, the Examiner has not
shown that the applied art teaches or suggests selecting a transgenic plant
based on its resistance to drought as recited in step (b ).
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Appeal2014-007925
Application 11/909,262
We accept Appellants' definition of the "drought stress" recited in
step (b) of claim 1. According to Appellants, "the drought stress being
evaluated in the claimed methods is stress that causes 'severe irreversible
wilting' in plants lacking the recombinant expression cassettes of the
invention." (App. Br. 9-10; see also id. at 2 ("the term 'drought stress'
refers to drought conditions that kill a control plant, but from which plants of
the invention survive.") This is consistent with Specification's description
of such severe drought conditions, and distinguishes from milder drought
stress in which unmodified plants are able to recover. For example,
Appellants disclose
[l]ong dehydration periods of 16 days caused severe irreversible
wilting of the WT [wild-type] plants and less severe, and
reversible wilting in plants carrying the pSARK:IPT.
Rehydration (rewatering of the dehydrated plants) caused
recovery of the transgenic pSARK:IPT plants, whereas the WT
plants could not be recovered (Fig. 1) from the drought stress.
(Spec. i-f 62; see also id. at i-f 63 (discussing 18-day drought where
"[r]ehydration of the plants for 14 days did not recover[] WT plants ... , but
fully recovered both transgenic lines.")6
We are not persuaded that Clark or Synkova discloses screening
transgenic plants for resistance to drought stress that causes severe
irreversible wilting as recited in claim 1. Instead, we agree with Appellants
6 Appellants also describe drought stress as follows: "drought stress (i.e.,
little or no water for a period of days). Typically, the drought stress will be
at least 5 days and can be as long as 18 to 20 days." (Spec. i-f 17.) Although
this description encompasses shorter periods of stress, Appellants' claims
expressly require drought that causes severe irreversible wilting in
untransformed plants.
5
Appeal2014-007925
Application 11/909,262
that Clark and Synkova imposed mild water deficits to study other
physiological processes in the subject plants. (App. Br. 10-12.)
For example, Clark concerned the interrelationship between
senescence, IPT, and cytokinin, and whether over-expression of IPT delays
senescence. (See Clark 93.) The mild water deficit described in Clark was
relevant as an environmental factor to trigger senescence, and thus induce
over-expression of IPT in plants genetically modified with an IPT gene
driven by the senescence-associated transcriptional promoter PsAG12. (Id. at
93-94.)7 The Examiner has not, however, explained adequately how a
delayed senescence phenotype exhibited in plants over-expressing IPT
translates to drought tolerance, nor why the skilled artisan would have
concluded that such plants are resistant to the drought stress recited in claim
1 and selected them accordingly. (App. Br. 11; Reply Br. 3--4.)
Synkova studied the effect of growth conditions (e.g., irradiation) and
water stress on growth and enzymatic activity of transgenic (Pssu-ipt) and
wild-type plants. (Synkova Abstract.) Appellants contend the "focus of
[Synkova's] research ... was not drought tolerance, but the study of plant
responses to reactive oxygen species in senescent tissues that occur in
response to mild water stress." (App. Br. 10.) Appellants emphasize that
7 Clark teaches "[t]he plants were watered to media saturation, then no
further irrigation was provided until the plants wilted from drought stress.
After a 24-h period of visible wilting, plants were irrigated with fertilizer
solution, then were maintained well-watered for 14 d." (Clark 95.)
Appellants note that subjecting Clark's control plants "to the drought
conditions required by the appealed claims would have led to death of the
control plants and would not have been useful in studying the effect of IPT
expression." (Reply Br. 4.)
6
Appeal2014-007925
Application I 1/909,262
Synkova imposed a period of mild water deficit to both the transgenic and
wild-type plants and, unlike the drought stress recited in the present claims,
all the plants including the wild-type in Synkova survived. (Id. at IO-I 1.)8
Appellants further point out
Figure I and 2 show that all of the wild type plants survived
treatment. The top panel of Figure I shows that wild-type (SRI)
plants were still growing under control ( c) and water stressed ( s)
conditions. Similarly, Figure 2 shows that water stressed wild
type plants (SR,s - black bars) had similar stem lengths, relative
water contents, and dry mass as compared to water stressed
transgenic plants (SE,s - cross hatched bars.) Clearly none of
the wild-type plants were subjected to conditions that caused
severe irreversible wilting.
(Reply Br. 3--4.) On the present record, we are not persuaded that
Appellants' interpretation of Synkova is incorrect. 9
The Examiner cites Synkova's Abstract, and page 5I6 including
Figures I and 2 appearing on that page, but the Examiner has provided
insufficient findings or rationale to explain how those portions of Synkova
teach or suggest the drought tolerance recited in claim I. "[R ]ejections on
obviousness grounds cannot be sustained by mere conclusory statements;
instead, there must be some articulated reasoning with some rational
8 Synkova teaches "[w]ater stressed plants were subjected for a period of 4
weeks to a cycle of a water-deficit programme, i.e., 3 days withholding
irrigation was followed by re-watering." (Synkova 5I5.)
9 Synkova does teach that "higher DM [dry mass] and FM [fresh mass] per
unit of leaf area were found in both transgenic grafts and plants as compared
with SRI [wild-type]." (Synkova 5I6.) Even if Synkova teaches somewhat
greater growth of transgenic plants exposed to mild drought conditions, on
the present record, it is unclear whether such growth would be advantageous
or disadvantageous for long or short-term drought resistance.
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Appeal2014-007925
Application 11/909,262
underpinning to support the legal conclusion of obviousness." KSR Int' I Co.
v. Teleflex Inc., 550 U.S. 398, 418 (2007) (quoting In re Kahn, 441 F.3d
977, 988 (Fed. Cir. 2006). While not the focus of a specific finding by the
Examiner, Synkova does teach that "higher DM [dry mass] and FM [fresh
mass] per unit of leaf area were found in both transgenic grafts and plants as
compared with SRI [wild-type]." (Synkova 516.) It is, however, unclear
whether such increased growth during the cyclic water stress imposed in
Synkova has any connection to drought resistance in transgenic plants -
especially drought that causes severe irreversible wilting in wild-type
plants. 10 The Examiner has cited nothing in Synkova or in the other cited
references making that connection.
For the above reasons, we conclude the Examiner has not established
that claim 1 would have been prima facie obvious over Gepstein, Synkova,
and Clark. Because we conclude that the Examiner did not establish a prima
facie case, we decline to address Appellants' arguments concerning alleged
surprising results provided by the claimed method. (App. Br. 14--15.)
We reverse the rejection of claim 1 over Gepstein, Synkova, and
Clark. Claims 3, 5-7, and 9-12 depend (directly or indirectly) from claim 1
so we reverse the rejection as to those claims as well.
As to the rejection of claim 8 over Gepstein, Synkova, Clark, and
Zinselmeier, the Examiner cites Zinselmeier as teaching "a nucleotide
sequence encoding the isopentenyl transferase (SEQ ID NO: 3) ... [that]
10 Appellants have presented evidence that, at the time of the invention, a
delayed-senescence phenotype would have been considered disadvantageous
and thought to make plants more susceptible to drought. (App. Br. 14; Oct.
2, 2009 Deel. of Eduardo Blumwald, Ph.D. i-f 6.)
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Appeal2014-007925
Application 11/909,262
improves cell division when over-expressed in a plant." (Final Act. 5.) We
agree with Appellants that the "Examiner points to nothing in Zinselmeier
that addresses the shortcomings of [Gepstein, Synkova, and Clark]" and thus
we reverse the rejection of claim 8 as well. (App. Br. 15.)
SUMMARY
We reverse the rejection of claims 1, 3, 5-7, and 9-12 under 35
U.S.C. § 103(a) over Gepstein, Synkova, and Clark. We also reverse the
rejection of claim 8 under 35 U.S.C. § 103(a) over Gepstein, Synkova,
Clark, and Zinselmeier.
REVERSED
9