全 文 ：第 29 卷 第 1 期 作　物　学　报 V o l. 29, N o. 1
2003 年 1 月　 59～ 62 A CTA A GRONOM ICA S IN ICA pp. 59～ 62　 Jan. , 2003
The Changes and Com ponen ts of Non -photochem ica l Quench ing under D rought
and Shade Cond ition s in M a ize
ZHAO M ing3 , 1　D IN G Zai2Song1　R Ishh ill2　CH EN L i2　ZHAN G Xu1
(1 Colleg e of C rop S cience, Ch ina A g ricu ltu ra l U niversity , B eij ing 100094, Ch ina; 2 C rop S cience L abora tory , G rad ua te S chool of A g ricu ltu ra l
and L if e S cience F acu lty , T oky o U niversity , B unky o2ku, T oky o 113, J ap an)
Abstract　D rough t and shade condit ion s are facto rs of lim it ing m aize (Z ea m ay s L. ) pho to syn thesis fo r
h igh yield. In o rder to ob serve the respon ses of non2pho tochem ica l ch lo rophyll f luo rescence quench ing
(qN ) as w ell as the change cou rses and com ponen ts of qN to drough t and shade stresses, these param eters
w ere m easu red in d ifferen t t rea tm en ts. T he resu lts show ed tha t: ( 1) D rough t and shade trea tm en ts
m arkedly increased qN s and qN m ax , w h ich w as non2pho tochem ica l quench ing a t the m ax im um and stab le
stage respect ively, and decreased the quan tum yield of PS II pho tochem istry (5 PSÊ ). (2) T he ra t io of qN s
to qN m ax co rresponded to the severity of st resses, and its changes betw een differen t t rea tm en ts w ere sim ila r
to tha t of rela t ive decrease of p lan t dry m atter w eigh t (RDDMW ). (3) D rough t and shade effected, to cer2
ta in degree, the t im e and ra te of qN to reach the m ax im um o r stab le stage (T qNm ax , R qNm ax , T qN s and R qN s).
T he m o st im po rtan t param eter R qN s w as low est in the severe drough t and shade trea tm en ts (DD and SS) ,
low er in trea tm en ts of recovering from drough t and shade condit ion s (DR and SR ) , and h ighest in con tro l.
T he changes in R qN s w ere a lm o st iden t ica l w ith tha t of p lan t dry m atter w eigh t. (4) T he shade trea tm en ts
m ain ly increased energy2dependen t quench ing ( qE ) , how ever, d rough t t rea tm en ts m ain ly increased
quench ing rela ted to sta te t ran sit ion s (qT ).
Key words　M aize; D rough t and shade stresses; N on2pho tochem ica l quench ing
干旱和遮光条件下玉米非光化学荧光猝灭的变化和组成的研究Ξ
赵　明3 , 1　丁在松1　R Ishh ill2　陈　鹂2　张　旭1
(1中国农业大学作物学院, 北京 100094; 2日本东京大学农学学部)
摘　要　干旱和光照不足是干扰玉米光合作用, 进而影响玉米高产的重要限制因素。为了了解玉米叶绿素非光化学荧光
猝灭 (qN )对干旱和遮光逆境的反应, 我们研究了 qN 的主要叶绿素荧光参数。结果表明: (1) 干旱和遮光处理显著增加
了最大值时的 qN m ax和稳定态时的 qN s, 降低了 PSÊ 电子传递的光量子产量 (5 PSÊ )。(2) qN s 与 qN m ax的比值与逆境的严
重程度相符合, 它在各处理间的变化趋势与植株干物重减少的百分率 (RDDMW )一致。(3) 干旱和遮光在一定程度上影
响了 qN 到达最大值或稳定态的时间和速率。其中 qN 到达稳定态的速率 (R qN s) 是一个非常有意义的指标, 它在严重的
干旱 (DD )和遮光 (SS)处理下最低, 在较轻的干旱 (DR ) 和遮光 (SR ) 处理下较低, 在对照中最高。R qN s在各处理间的变化
趋势与植株干物重基本一致。 (4) 遮光处理主要增加与能量耗散有关的 qN 的快组分 (qE) , 而干旱处理主要增加与状态
转换有关的 qN 的中组分 (qT )。
关键词　玉米; 干旱和遮光逆境; 非光化学荧光猝灭
中图分类号: S513　　　文献标识码: A
　　D rough t and w eak ligh t in canopy affect m any
p rocesses of pho to syn thesis. D rough t frequen t ly
cau ses rap id stom ata clo su re, w ith the reduct ion of
w ater lo ss th rough tran sp ira t ion, the decrease of
in terna l CO 2 concen tra t ion, and the decline in leaf
pho to syn thet ic ra te. Concom itan t ly, inh ib it ion o r
dam ages in the p rim ary pho tochem ica l p rocesses
m ay occu r[ 1, 2 ]. M eanw h ile, ligh t deficiency is veryΞ 基金项目: T he State Key Basic Research and D evelopm ent P lan (G1998010100)
　 3 作者简介: A utho r fo r co rrespondence
Received on (收稿日期) : 2001202213, A ccep ted on (接受日期) : 2002203212

comm on in som e circum stances du ring m aize
grow th, especia lly in the condit ion s of h igh p lan t
den sity. Ch lo rophyll f luo rescence k inet ics revea led
com p lex changes in energy balance in the in terio r
thylako id, and each phase of the ch lo rophyll f luo2
rescence induct ion cu rve resu lted from a part icu la r
b iophysica löb iochem ica l p rocess governed by the
energy flux th rough p ro teinaceou s com p lexes in
thylako ids. It has been know n tha t qN can be sep2
ara ted in to th ree com ponen ts based on dark to ligh t
relaxa t ion k inet ics. T hese com ponen ts of qN , in
o rder from the faster to the slow est relaxa t ion, a re
energy2dependen t quench ing (qE) , sta te t ran sit ion
quench ing ( qT ) and pho to inh ib ito ry quench ing
(q I) [ 3 ]. T hese fluo rescence param eters have been
u sed fo r the eva lu t ion of st ress resistance o r sen si2
t ivity in variou s crop p lan ts[ 4 ].
In the p reviou s stud ies, w e have found tha t
the non2pho tochem ica l ch lo rophyll f luo rescence
quench i2
ng (qN ) had a m arked and im po rtan t change char2
acterist ics. It cou ld be analyzed acco rd ing to the
t im e and the ra te to reach the m ax im um and stab le
stage, w h ich w as defined as T qNm ax , R qNm ax , T qN s
and R qN s respect ively. T he T qN s and R qN s in m aize
w as 3～ 5 t im es longer and slow er than tha t in
w heat. In th is w o rk, the effects of drough t and
shade stresses on changes and com ponen ts of qN in
m aize w ere invest iga ted. T hese fluo rescence pa2
ram eters w ere m easu red and com pared w ith p lan t
dry m atter w eigh ts in m aize under d ifferen t
drough t and shade trea tm en ts in o rder to find the
rela t ion betw een the fluo rescence param eters and
the dam age degrees under d ifferen t st resses.
1　M a ter ia ls and M ethods
1. 1　Plan ts
Tw o m aize hyb rids (H 1: N ongda108, H 2:
D K789 ) and tw o inb red lines ( I1: P178, I2:
H uangC) w ere cu ltu red in a greenhou se in Tokyo
un iversity from 30th A p ril to 15th A ugu st, 1999.
M aize seeds w ere sow n in 14. 8L po ts, and each
po t had on ly one p lan t. T he average tem pera tu re
in greenhou se w as 33. 5ö27. 5C (dayön igh t ) and
the ligh t in ten sity w as 615 ΛEm - 2 s- 1.
1. 2　Trea tm en ts of drought and shade
F ive trea tm en ts w ere desined in th is experi2
m en2
t, they w ere as fo llow ed:
Con tro l: T he p lan ts w ere w atered th ree t im es
one w eek and grew no rm ally w ithou t w ilt ing. So il
rela t ive w ater con ten t in the po ts had been kep t a t
85%～ 90% of m ax im um so il w ater con ten t.
DD: Bo th the frequency and the quan t ity of
w atering w ere decreased to a quarter of the con tro l
du ring the t im e of 40 days from the six th leaf ex2
panded ( 6 th June ) to gra in filling period ( 15th
Ju ly). So il rela t ive w ater con ten t had been kep t a t
70%～ 75% of m ax im um so il w ater con ten t.
DR: Bo th the frequency and the quan t ity of
w atering w ere decreased to a quarter of the con tro l
du ring the t im e of 20 days from the six th leaf ex2
panded (6th June) to the tw elfth leaf expanded (26th
June). So il rela t ive w ater con ten t had been kep t as
sam e as DD. T hen w atering w as recovered to the
sam e as con tro l.
SS: T he p lan ts w ere shaded w ith b lack gauze
so tha t a quarter ligh t in ten sity of con tro l had been
kep t from the six th leaf expanded ( 6th June ) to
gra in filling period (15th Ju ly). W atering w as the
sam e as con tro l.
SR: T he p lan ts w ere shade du ring the t im e of
20 days from the six th leaf expanded (6th June) to
tw elfth leaf expanded (26th June) and after then re2
leased the shade trea tm en t.
1. 3　Chlorophyll f luorescence m ea surem en t
Ch lo rophyll f luo rescence w as m easu red w ith a
fluo rom eter ( PAM 2101, W alz, Effelt rich,
Germ any) ju st after the trea tm en t (15th Ju ly). T he
dark adap ta t ion periods w ere m o re than 30 m in2
u tes, du ring w h ich the m iddle po sit ion of the
leaves near ear w as covered w ith t info il paper.
T hen these eaves w ere cu t and kep t in w ater and
m oved in to the labo ra to ry fo r m easu rem en t. T he
act in ic irrad iance w as 250 Λm o l m - 2 s- 1, and sa tu2
ra ted flashes of 11, 000 Λm o l m - 2 s- 1 w ere fired ev2
ery 30 seconds. T he fluo rescence param eters w ere
ana lyzed by PAM 22000 softw are. T he changes of
06　　　　　　　　　　　　　　　　　　　　　作　　物 　　学　　报　　　　　　　　 　　　　　　　　　　　29 卷

qN w ere defined as show n in F ig. 1.
F ig. 1　　T he defin it ion of non2pho tochem ical quench ing changes
R qNm ax= qNm axöT qNm ax　　R qN s= (qNm ax- qN s) ö(T qNm ax- T qN s)
2　Results
2. 1　Chlorophyll f luorescence character ist ics and
plan t dry ma tter production under d ifferen t
drought and shade cond ition s
A s show n in T ab le 1, d ifferen t drough t and
shade trea tm en ts a ll increased qN s, qN m ax and qN sö
qN m ax , and decreased 5 PSÊ and RDDMW. T he re2
su lts dem on stra ted tha t under drough t and shade
stresses the ra te con stan t of therm al d issipa t ion of
excita t ion energy by PS Ê w as increased and the
ra te con stan t of PS Ê pho tochem istry w ere de2
creased. U nder severe drough t t rea tm en t (DD ) ,
these tra its varied m uch m o re than o ther t rea t2
m en ts. It suggested tha t severe drough t leaded to a
grea ter dam age to the pho to syn thet ic system as
w ell as the p lan t grow th in m aize.
T he ra t io of qN s to qN m ax w as u sed to ana lyze
the dynam ics of non2pho tochem ica l quench ing from
m ax im um value to steady sta te fo r find ing its rela2
t ion w ith stresses. T he resu lts show ed tha t qN sö
qN m ax w as h ighest in DD and SS, h igher in DR and
SR , and the low est in con tro l. It ind ica ted tha t
qN söqN m ax m igh t co rrespond to the severity of
st resses. T he decrease in qN after reach ing the
peak m ay be affected by stress t rea tm en ts.
Com parison of the rela t ive decrease in p lan t
dry m atter w eigh t (RDDMW ) am ong differen t
drough t and shade trea tm en ts show ed tha t RD 2
DMW w as h igher in DD and SS and low er in DR
and SR. RDDMW w as regarded as the fina l resu lts
of st resses on the m aize p lan ts. T he changes in
RDDMW w ere sim ila r to tha t of qN söqN m ax. So
qN söqN m ax m ay be a bet ter param eter fo r m easu ring
the affect ion of drough t o r shade stresses on m aize
p lan ts.
Table 1　　Appearance of qN, 5 PSÊ and RDDMW under
differen t drought and shade condition s
T reatm ent qN s qNm ax qN söqNm ax 5 PSÊ RDDMW (% )
Contro l 0. 402 0. 772 0. 521 0. 653 0
DD 0. 927 0. 935 0. 991 0. 239 44. 5
DR 0. 625 0. 841 0. 743 0. 422 14. 0
SS 0. 763 0. 862 0. 885 0. 472 68. 9
SR 0. 624 0. 885 0. 705 0. 440 32. 1
　　N o te: RDDMW m eans relat ive decrease of dry m atters w eigh t,
it w as defined as (12t reatm entöcontro l×100)
2. 2　The changes of non -photochem ica l quench ing
under d ifferen t drought and shade cond ition s
T he t im e (T qNm ax and T qN s) and ra te (R qNm ax and
R qN s) of qN m easu red after dark adap t it ion in m aize
w ere ana lyzed. T he reau lts ( in T ab le 2) show ed
tha t drough t and shade trea tm en ts a lso affected the
t im e and ra te of qN to som e degree. T he m o st im 2
po rtan t param eter R qN s, w h ich w as ra te of qN from
m ax im um peak to steady sta te w hen illum ina t ing
after dark adap ta t ion, w as low est in severe
drough t and shade trea tm en ts (DD and SS) , low er
in trea tm en ts of recovering from drough t and shade
condit ion s (DR and SR ) and the h ighest in con2
t ro l. T he varia t ion of R qN s w as alm o st iden t ica l
w ith tha t of rela t ive dry m atter w eigh t (RDMW )
am ong all the trea tm en ts. It m ean s tha t bo th
drough t and shade stresses can affect the ra te of
qN from m aixm um to steady sta te in m aize leaves.
Table 2　　The time (TqNmax and TqNs) and rate (RqNmax and
RqNs) of qN measured af ter dark adaptiation in ma ize
T rea2
tm ent
T qNm ax T qN s R qNm ax R qN s
RDMW
(% )
Contro l 5. 50±0. 61 20. 50±6. 65 7. 07±1. 96 1. 44±0. 78 100
DD 8. 18±3. 57 25. 23±5. 76 6. 83±4. 36 0. 54±0. 23 55. 5
DR 8. 14±2. 56 21. 38±9. 83 7. 65±2. 97 1. 33±1. 68 86. 0
SS 6. 83±1. 31 17. 27±7. 68 5. 81±0. 53 0. 72±0. 35 31. 1
SR 5. 50±2. 67 14. 75±6. 72 7. 95±3. 18 1. 22±0. 21 67. 9
2. 3　The com ponen ts of non -photochem ica l
quenc-
h ing under d ifferen t drought and shade cond ition s
T he analysis of non2pho tochem ica l com po2
161 期　ZHAO M ing et a l. : T he Changes and Componen ts of N on2pho tochem ical Q uench ing⋯⋯　　　

nen ts under d ifferen t drough t and shade trea tm en ts
w as conducted. T he resu lts ( in T ab le 3) show ed
tha t shade trea tm en ts ( includ ing SS and SR ) in2
cresed qE, w h ich w as m o re than 0. 4. How ever,
d rough t t rea tm en ts ( includ ing DD and DR ) in2
creased qT , w h ich w as m o re than 0. 3. It im p lied
tha t qE and qT p layed an im po rtan t ro le in re2
sponding to stress condit ion s. Energy2dependen t
quench ing (qE) is associa ted w ith the m agn itude of
the tran sthyako id p ro ton grad ien t, w h ich is fo rm ed
du ring linear o r cyclic electron tran spo rt [ 5 ].
Q uench ing rela ted to sta te t ran sit ion s ( qT ) in2
vo lves the reversib le pho spho ryla t ion of ligh t2har2
vest ing p ro tein s and are though t to be im po rtan t in
ba lancing the d ist ribu t ion of ligh t energy betw een
Pho to system s I and II a t low ligh t [ 6 ].
Table 3　　The componen ts of qN under differen t drought
and shade condition s in ma ize
T reatm ent qE qT q I
Contro l 0. 317±0. 166 0. 279±0. 148 0. 176±0. 084
DD 0. 354±0. 177 0. 329±0. 165 0. 167±0. 030
DR 0. 280±0. 058 0. 384±0. 098 0. 177±0. 052
SS 0. 450±0. 095 0. 228±0. 082 0. 185±0. 031
SR 0. 406±0. 230 0. 317±0. 286 0. 162±0. 055
3　D iscuss ion
　　 It is genera lly believed tha t qN rep resen ts a
non2rad ia t ive d issipa t ion of excita t ion energy as
hea t and can be a pho top ro tect ive st ra tegy. L u and
Zhang [ 7 ] found an increase in non2pho tochem ica l
quench ing and a decrease in the quan tum yield of
PS II electron tran spo rt (5 PSÊ ) in senescen t leaves of
m aize p lan ts. In the resu lts of th is paper, d rough t
and shade trea tm en ts m arkedly increased qN and
decreased 5 PSÊ , suggest ing tha t the PS Ê pho to2
chem ica l act ivity w as low ered in drough t and shade
stresses and the m o re therm al d issipa t ion of excita2
t ion energy occu rred.
T heo ret ica lly, RDDMW shou ld be linearly re2
la ted to decrease in 5 PSÊ , bu t ou r resu lts appeared
differen t ly. T he 5 PSÊ of DD trea tm en t w as m uch
m o re than tha t of SS trea tm en t, bu t the dry m atter
w eigh t of SS trea tm en t w as the low est am ong all
the trea tm en ts and m uch less than tha t of DD
trea tm en t. It w as p robab ly becau se tha t du ring SS
trea tm en t 5 PSÊ of m aize p lan ts cou ld be a lso very
low and grea t ly decreased the dry m atter w eigh t.
How ever, the m easu rem en t w as conducted after
the shade w as rem oved and 5 PSÊ recovered m o re
rap id ly.
T he resu lts of ou r p reviou s study show ed tha t
the m ain cau se of d ifference in qN changes betw een
m aize and w heat w as no t rela ted to CO 2 assim ila2
t ion sta rt2up , stom atic regu la t ion o r PSÉ ox id iza2
t ion po ten t ia l w hen illum ina t ing after g iven t im e of
dark adap ta t ion. In stead, it p rim arily depended on
the qE fo rm at ion. In o ther w o rds, m aize leaves
needed m o re energy fo r m ain ta in ing p ro ton grad i2
en t of thylako id to adap t the strong rad ia t ion after
adap ta t ion. In th is w o rk, w e also found tha t shade
and drough t t rea tm en ts affected the changes and
com ponen ts of m aize non2pho tochem ica l quench2
ing. T he rela t ion betw een stresses and non2pho to2
chem ica l quench ing changes needs m o re researches
in the fu tu re.
References
[ 1 ]　B joβkm an O , Pow les S B. Inh ib it ion of pho to syntheitc reac2
t ions under w ater stree: in teraction w ith ligh t level. P lan ta,
1984, 161: 490～ 504
[ 2 ]　KaiserW M. Effects of w ater deficit on pho to synthetic capaci2
ty. P hy siol P lan tarum , 1987, 71: 142～ 149
[ 3 ]　Ho rton P, Ruban A V , W alters R. G . Regulation of ligh t
harvesting in green p lan ts. A nnu R ev P lan t P hy siol P lan tM ol
B iol. 1996, 47: 655～ 684
[ 4 ]　L in S2Q (林世青) , Xu C2H (许春晖) , Zhang Q 2D (张其德) ,
et a l. Som e app lication of ch lo rophyll fluo rescence k inetics to
p lan t stress physio logy, phytoeco logy and agricu ltu ral mod2
ern ization. Ch inese B u lletin of B otany (植物学通报). 1992, 9
(1) : 1～ 16
[ 5 ]　B rian tais J M , V erno tte C M , Kraus G H. A quantitat ive
study of the slow decline of ch lo rophyll fluo rescence in iso lat2
ed ch lo rop last. B ioch im B iop hy s A cta, 1979, 548: 128～ 138
[ 6 ]　M axw ell K, Johnson G N. Ch lo rophyll fluo rescence2a p ractical
gu ide. J ou rna l of E xp erim en ta l B otany , 2000, 51 (345) : 659～
668
[ 7 ]　L u C M , Zhang J H. M odifications in pho to system Ê pho to2
chem istry in senescen t leaves of m aize p lan ts. J ou rna l of E x2
p erim en ta l B otany , 1998, 49 (327) : 1671～ 1679
26　　　　　　　　　　　　　　　　　　　　　作　　物 　　学　　报　　　　　　　　 　　　　　　　　　　　29 卷